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Velp Scientifica 

– UDK139 Operating Manual  

10004762/B5

 

92 

22 - Kjeldahl method to determine the protein content on 
mushrooms 

 
The average protein content on fresh mushrooms is 2-4%. 
 

Procedure 

1) Sample:

 10g of ground dried sample. 

2) Reagents for digestion:

 for each sample add in the test tube: 

 

2 catalyst tablets ST (code CT0006609) 
15 ml concentrated sulphuric acid (96-98%) 
 
shake gently the tube with the sample. 
 

3) Digestion:

 heat for 60 min at 420 °C. 

 

4) Cooling:

 let cool the tubes to 50-60 °C.  

 

5) Distillation-titration:

 place in position the test tube with digested sample in the 

unit UDK 139. 
 
factor: 6.25 
 
Reagents addition: 
dilution water=50ml 
 H

3

BO

3

=30ml 

 NaOH=50 ml 
 
Titrant: HCl 0.2N 
Distillation time= 4 min  
Steam power= 100% 
Press the button starting distillation cycle. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 

 References:

 

AOAC, “Official methods of analysis”, method 976.06 

279

Summary of Contents for UDK 139

Page 1: ...liquids do not come into contact with the electric power cable or with the electrical parts of the instrument Check that the power supply corresponds to the rating plate on the rear of the unit When replacing the power cable make sure that the new cable has the same characteristics as the original and that it is earthed Do not use the unit if it is not working correctly In case of malfunctioning c...

Page 2: ...irer le tube à la fin de la distillation Les récipients et les produits utilisés pendant les analyses doivent être compatibles avec la température réglée sur l appareil environ 100 C Pour toute autre information sur l utilisation des réactifs utilisés voir Chapitre 2 Produits chimiques S assurer que la protection transparente est en place lorsque l appareil fonctionne Respecter les instructions d ...

Page 3: ... 2 Reserves and overfilling 43 5 1 3 Warning signals and messages 44 5 1 4 Black out 45 5 2 Graph of steam production 45 5 3 Graph of tap water consumption related to the water flow rate and temperature 46 6 Work cycle 47 6 1 Analysis 47 6 2 Devarda s analysis 47 7 End of work operations 48 8 Maintenance 49 8 1 Routine maintenance 49 8 2 Extraordinary maintenance 50 8 2 1 Periodic maintenance 50 8...

Page 4: ... grain spaghetti macaroni 90 21 Kjeldahl method to determine the protein content on plants vegetable 91 22 Kjeldahl method to determine the protein content on mushrooms 92 23 Kjeldahl method to determine total nitrogen on crude oil and fuels ISO n 333 93 24 Kjeldahl method to determine total nitrogen on ABS SAN rubber 94 25 Kjeldahl method to determine total nitrogen in urea 95 26 Kjeldahl method ...

Page 5: ... UDK 139 Semi automatic Distillation Unit has a color touch screen with electronic control for simple and user friendly programming of parameters such as distillation time the volume of reagents such as sodium hydroxide water and the regulation of steam production from 10 to 100 in order to carry out Semi automatic distillation By modifying the distillation time and steam output it is possible to ...

Page 6: ...er for test tube 10000247 1 Touch pen 10004936 1 Inlet tube 10000280 1 Tubes with sensors Inlet tube for H2O Inlet tube for NaOH Outlet tube for distillation residues 40000153 40001023 40000387 3 Discharge tubes Silicone tube Ø 6x9mm PVC tube Ø10x14 10000020 10001087 2 The operating manual is inside the distillation unit1 box The test tube2 is not sold separately see chap 10 Accessories The protec...

Page 7: ...cally Main components of the distillation unit 1 Color Touch Screen with protective film 2 On Off switch 3 Service door catch 4 Flask stand 5 Safety guard 6 Lever for insertion of test tube 7 Test tube press 8 Test tube connection 9 Plastic guard for test tube connection 10 Socket panel 11 Distillate outlet tube The Semi automatic distillation unit UDK139 is fitted with innovative devices and is m...

Page 8: ... user to program all the automatic distillation titration parameters The protective film on the touch screen safeguards against wear and against the majority of laboratory agents Choose from 6 different languages to communicate with the instrument The distillation unit can be connected to a printer via USB in order to print all the information pertaining to the tests performed in accordance with G...

Page 9: ...eptional in providing savings by using TEMSTM technology Time Fast and frequent analyses no heating delay between runs Energy Cooling water consumption starting from only 0 5 l min excellent insulation of internal parts Money Cost reduction is substantial in line with reduced power consumption Space The extremely compact footprint saves useful laboratory bench space 196 ...

Page 10: ...versa Ingestion can cause vomiting prostration collapse Constrictive scarring can occur Caution in case of ingestion DO NOT attempt to evacuate the stomach Chemicals used during the digestion phase 3 Sulphuric Acid H2SO4 concentrated 96 98 Corrosive to all body tissues Skin contact can produce necrosis Protect the skin and the eyes When diluting the acid must be added to the diluent to prevent the...

Page 11: ...ory tract causing coughing and discomfort The fumes generated must be removed using efficient devices i e Recirculating Water Pump model JP code F30620198 and preferably neutralized before being released into the atmosphere i e Scrubber model SMS code F307C0199 2 Distillation residues containing toxic catalysts The use of toxic metals such as mercury selenium or copper as catalysts for digestion m...

Page 12: ... cooling the distillate with a maximum pressure of 5 bar and sink in order to discharge the waste water The instrument requires a tap water flow rate depending on the temperature of the tap water of approximately 0 5 l minute at a temperature of 15 C 1 l minute at a temperature of 30 C Water is required during the distilling phase only and is interrupted automatically during the other phases Posit...

Page 13: ...e to tubes and internal components Push the end of the tube with level sensor to the bottom of the corresponding carboy OUTLET Cooling Water Cooling water outlet Push the PVC tube supplied diameter 10x14 mm onto the corresponding tube holder by hand and place the other end of the tube in a sink drain Check the flow rate of the cooling water discharged from the condenser during the distillation tit...

Page 14: ...indicators will not be functional 3 2 Connection to the electric power supply Before connecting the instrument to the power supply make sure that the mains switch is turned off and that the values on the labels correspond to those of the power supply Make sure the electrical network is earthed Connect the instrument to the power supply using the cable and plug supplied The instrument requires a 22...

Page 15: ...3 4 Printer Connect the printer item code A00001009 to one of the two USB ports in order to obtain automatic print outs at the end of analysis The serial port configuration of the printer should be Baud rate 4800 Data length 8 Parity None Bit of Stop 1 Handshaking None Xon Xoff For printer connection a USB RS232 serial converter cable is required item code A00000195 Connect the RS232 converter plu...

Page 16: ...e tap water Check that the distillate tube is in place in the flask Turn the instrument on by pressing the mains switch POWER led on on the right of the instrument The instrument automatically carries out the following steps simultaneously Preheating this takes 3 minutes A yellow strip at the top of the display reading preheating indicates that preheating is in progress the countdown indicates the...

Page 17: ...d by the instrument and how to reach them easily Analysis Wash down Distillation Methods Set up Date Time Language Frequency Keyboard sounds Lab name Print Type Automatic System Check up Manual check up Automatic check up Diagnosis Check safety device Safety guard Safety test tube Safety lever Check inlet tubes Inlet tube for H2O Inlet tube for NaOH Residues tube Cooling H2O Calibration Cal H2O pu...

Page 18: ...Velp Scientifica UDK139 Operating Manual 10004762 B5 18 Cal NaOH pump Maintenance Clean NaOH circuit Clean filters Test tube connection N analyses Service Upload software Advanced settings 205 ...

Page 19: ...xception of work processes that require steam production An acoustic signal informs the operator that preheating is complete The band at the top of the display is now blue and reads UDK139 as well as giving the current date and time The second line gives the name of the menu viewed The main menu consists of 8 submenus that can be selected using the touch screen or the pointer of the mouse where pr...

Page 20: ...Velp Scientifica UDK139 Operating Manual 10004762 B5 20 In each sub menu the arrow in the upper left corner allows you to return to the previous screen 207 ...

Page 21: ...corner 4 3 1 Wash down During wash down distillation is carried out using distilled water as a reagent in order to wash the internal parts of the splash head and condenser Wash downs can be carried out at any time Use the touch screen to select Wash down the following window appears Pressing Distillation time the alphanumeric keypad appears Use it to set the wash down time min 2 00 max 7 30 208 ...

Page 22: ... possible to select or not the residues removing at the end of wash down with Yes or No To return to the Wash down menu press the arrow in the upper left corner To return to the Analysis menu press the arrow in the upper left corner To carry out a wash cycle press During the wash down cycle the following three phases are carried out Add H2O Washing Empty 209 ...

Page 23: ...recommends that a wash down is carried out every day before starting sample analysis and at the end of the daily work session 4 3 2 Distillation Select Distillation from the Analysis menu The following window appears To return to the Analysis menu press the arrow in the upper left corner Select the various fields and enter the required analysis parameters Press Method to access the Methods menu se...

Page 24: ...pears Enter the sample name max 13 characters using the alphanumeric keypad Press to confirm Press Q ty of sample and enter the sample quantity using the alphanumeric keypad Use the touch screen to select the unit of measure required and press to confirm Press Notes The following window appears 211 ...

Page 25: ...g three phases are carried out in sequence Add reagents Analysis Residues removal only if previously selected The green flag on the right indicates that the analysis was carried out correctly a red X indicates that the phase did not terminate correctly Press to interrupt the process at any time The distillation time countdown is shown on the display during analysis The name and quantity of the sam...

Page 26: ...elected and return to the Distillation menu in order to with a new analysis 4 4 Methods Select Methods from the Main menu The following window appears To return to the Main menu press the arrow in the upper left corner Press next page or previous page to scroll through the 20 customizable methods listed Use the touch screen to select the method required 213 ...

Page 27: ...volume of H2O Press to confirm Select NaOH volume and use the numeric keypad to enter or modify the volume of NaOH Press to confirm Select Pause and use the numeric keypad to enter or modify the time lapse between the entry of reagents and the beginning of steam production Press to confirm Select Distillation time and use the numeric keypad to enter or modify the distillation time steam production...

Page 28: ... the arrow top left Press to move to the next window Press to return to the previous window Select Date and use the numeric keypad to enter or modify the date Press to confirm Select Time and use the numeric keypad to enter or modify the time Press to confirm Select Language and use the touch screen to choose from the list of languages available Press to confirm 215 ...

Page 29: ...the touch screen to select YES NO to enable disable the acoustic signal when touch screen keys are pressed Press to confirm Select Laboratory name and use the alphanumeric keypad to enter or modify the name of the laboratory Press to confirm The name of the laboratory will be printed on the report Select Print The display shows Select Type and choose from the options available Standard Compressed ...

Page 30: ...m Standard Compressed VELP SCIENTIFICA Distillator UDK139 Software Version 1 0 0 ______________________ Date 20 09 2010 Time 14 49 Laboratory name Velp Scientifica Operator Paolo ID 4 Sample Milk Q ty sample 5 0000ml Method Test H2O 50ml NaOH 20ml Pause 00 00 Distill Time 03 00 Steam 100 Empty test tube Yes Notes ______________________ VELP SCIENTIFICA Distillator UDK139 Software Version 1 0 0 ___...

Page 31: ... the Main menu press the arrow top left 4 6 1 Check up Select Check up from the Main menu The three sub menus are shown below To return to the System menu press the arrow in the upper left corner The Check up menu is used to fill empty the hydraulic circuits of the reagents these checks can be carried automatically or manually at any time 218 ...

Page 32: ...t to fill the dilution water circuit Press to start filling The green flag on the right indicates that the operation was carried out correctly a red X indicates that the operation was not successful Select Fill NaOH circuit to fill the sodium hydroxide circuit Press to start filling The green flag on the right indicates that the operation was carried out correctly a red X indicates that the operat...

Page 33: ... of the procedure one or more operations are marked with a red X press the back arrow to return to the Check up menu Select Manual check up and carry out the manual procedure for the option that failed during the automatic control NOTE if a check up has failed identify the cause before repeating the operation Diagnosis This option is used to check the correct functioning of safety devices level se...

Page 34: ...nstructions on the display The green flag on the right indicates that the operation was carried out correctly a red X indicates that the operation was not successful The procedure can be interrupted at any time by pressing Select Safety test tube The display shows Press and follow the instructions on the display 221 ...

Page 35: ...he instructions on the display The green flag on the right indicates that the operation was carried out correctly a red X indicates that the operation was not successful The procedure can be interrupted at any time by pressing Press the arrow top left to return to the Diagnosis menu It is also possible to check the correct functioning of the level sensors on the tubes supplied with the instrument ...

Page 36: ...hat the operation was not successful The procedure can be interrupted at any time by pressing Press the button Inlet tube NaOH The display shows the following screen Press and follow the instruction on display The green flag on the right indicates that the operation was carried out correctly a red X indicates that the operation was not successful The procedure can be interrupted at any time by pre...

Page 37: ...essful The procedure can be interrupted at any time by pressing Press the arrow top left to return to the Diagnosis menu Select Check cooling water The display shows Press to check the correct flow of cooling water in the hydraulic circuit The green flag on the right indicates that the operation was carried out correctly a red X indicates that the operation was not successful The procedure can be ...

Page 38: ...ibrate the flow rate of the reagent pumps NOTE Make sure that the hydraulic circuits are filled before calibrating see Check up Select H2O pump calibration The display shows Press to begin the process The instrument measures 50ml of diluting water Transfer the reagent diluting water to a graduated cylinder to measure the real volume Use the numeric keypad to enter the real volume press confirm Rep...

Page 39: ... is replaced or if a different concentration of NaOH is used 4 6 3 Maintenance Select Maintenance from the System menu The following submenus are listed To return to the System menu press the arrow top left Each line shows the type of maintenance followed by the number of analyses performed since the last maintenance was carried out and the recommended maintenance interval The maintenance interval...

Page 40: ...acing the test tube connection After 500 analyses from the last maintenance 1000 analyses in case of replacing the test tube connection when the instrument is turned on a prompt recommends that maintenance be carried out If the operator chooses to defer maintenance the prompt is repeated after an additional 20 analyses In that case the maintenance interval is updated too e g from 500 to 520 Press ...

Page 41: ...re was uploaded correctly a red X indicates that the procedure failed In this case check that the USB pen drive is in good working order that it is inserted properly in the USB socket and that the name of the file is UDK139_update zip Follow the instructions on the display to complete the upgrade procedure If there is a power failure during upgrade restore the electricity and turn the instrument o...

Page 42: ...essed An acoustic signal warns the operator of an error and the following warning message appears on the display AL4 Close protection If the safety guard is opened during a work cycle an acoustic signal warns of the danger the above warning message appears and the instrument continues the work cycle in progress Safety lever If the lever is not released analysis will not start when START is pressed...

Page 43: ...with level sensors from the tanks as this cause a partial emptying of the tubes When a reagent is in reserve the tank should be topped up rather than replaced in order to avoid emptying the tubes If a tank is replaced fill the tubes as described in Check up Chapter 4 6 1 Overfilling The unit is fitted with a dedicated hydraulic circuit for the removal of distillation residues which are conveyed to...

Page 44: ...as been changed between analyses If the test tube has not been changed when START is pressed an acoustic signal warns the operator of the error and the display shows the following message AL11 Change test tube Press Start to start the cycle without changing the test tube Warning messages Preheating When the instrument is turned on a yellow stripe at the top of every page of the software warns the ...

Page 45: ...e time required to produce 100ml of distillate at different steam production rates is shown in the following graph The UDK139 Semi automatic Distillation Unit can produce 100ml of distillate in just 4 minutes see graph Steam production can be set from 10 to 100 in order to perform fast or slow distillations 0 5 10 15 20 25 30 35 40 0 10 20 30 40 50 60 70 80 90 100 110 DISTILLATION TIME min STEAM F...

Page 46: ...e of 35 C in order to avoid loss of nitrogen As shown in the graph a distillate temperature of 34 C is obtained by the titanium condenser using tap water at a temperature of 31 C The temperature of the distillate using a conventional glass condenser would be 41 C under the same conditions The titanium condenser is also highly efficiency at low temperatures With a tap water temperature of 21 C a di...

Page 47: ...le name sample quantity distillation time 14 Start analysis 15 An acoustic signal indicates that the work cycle has terminated 16 Remove the test tube and replace it with a new sample If distillation series has finished place an empty test tube in the unit 17 Press to start a new analysis 6 2 Devarda s analysis 1 Switch on the instrument using the ON OFF switch on the rh side of the instrument 2 T...

Page 48: ...w sample If distillation series has finished place an empty test tube in the unit 17 Press to start a new analysis 7 End of work operations Before turning the instrument off at the end of the working day carry out a wash down from the Analysis menu At the end of the wash cycles 1 Turn off the tap water 2 Switch off the unit NOTE Always leave an empty test tube in place to avoid drips 235 ...

Page 49: ...t tube connection Servicing the instrument routine and extraordinary maintenance is very important to keep the unit in good working order and to extend its life time Follow the instructions given below 8 1 Routine maintenance Routine maintenance should be carried out at the end of each use Follow the instructions below Carry out a Wash down before turning off the unit by selecting Wash down from t...

Page 50: ...he inside of the safety guard 8 2 1 Periodic maintenance Cleaning the sodium hydroxide tubes Frequency every 500 analyses These tubes must be kept full at all times When the sodium hydroxide solution comes into contact with air crystals are formed which obstruct the tubes and jeopardize the correct functioning of the internal parts The tubes must be cleaned as part of extraordinary maintenance ope...

Page 51: ...ry 1000 analyses The test tube connection must be replaced when it loses its elasticity when it looks deformed and does not provide a perfect seal or after 500 analyses For easier removal carry out a wash down cycle The splash head can reach high temperatures therefore take care when handling Open the safety guard Remove the test tube the test tube connection and the safety guard The following tip...

Page 52: ...the emptying of the hydraulic circuit and the condenser 2 Open the service door of the instrument 3 Remove the metal clamp that supports the condenser by removing two screws 4 Detatch the black tube from the condenser inlet and outlet and remove it from the instrument 5 Unscrew the screw on the bottom flange of the condenser 6 Unscrew the two white bushings on both flanges of the condenser 7 Remov...

Page 53: ...inlet tubes from their containers and turn them upside down to prevent the reserve message appearing Follow the instructions for filling the tubes in System Check up Manual Check up to empty them completely Suck warm distilled water approx 40 C into the sodium hydroxide tubes to remove any crystals from the tubes and from the internal parts that come into contact with the NaOH Empty the circuit by...

Page 54: ...ctive 2002 96 CE For more information please contact the relative division of your local town council 10 Accessories Description Code Test tube Ø 80x300 mm for alcohol determination A00001083 Test tube Ø 48x260 mm 300 ml A00001088 Test tube diam 42x300mm 250ml 3 pcs box A00000144 Test tube diam 26x300mm 100ml 6 pcs box A00000146 Test tube Ø 50x300mm 400ml A00000185 Spacer for test tube Ø 48x260 mm...

Page 55: ...for test tubes 10000247 Touch pen 10004936 Protective film for touch screen Retarded ceramic fuse 6 3x32mm 15A 250V 40001798 10006304 The above mentioned spare parts can be easily replaced by the operator For other spare parts and for the complete list please contact Velp Scientifica Srl s nearest Service Centre Replace the fuses only when necessary i e if the unit doesn t turn on and the mains sw...

Page 56: ...idues tank Overflow signal Pollution degree 2 Overvoltage category II Max Altitude m 4000 Max Admitted humidity Max 85 Storage temperature range C 5 60 F 41 140 Ambient temperature range C 5 40 F 41 104 Fuses A 2x15A 250V Sound Level dBA 35 PERFORMANCES Nitrogen amount mgN 0 1 200 Reproducibility 1 Recovery rate 99 5 Detection limit mgN 0 1 Distilling time min sec 4 00 for 100ml of distillate at 1...

Page 57: ...ds H2O addition from 0 to 200 ml NaOH addition from 0 to 150 ml Pause from 00 00 to 99 59 Distillation time up to 99 59 Steam power from 10 to 100 Distillation residues aspiration Yes No ANALYSIS DATA The following parameters can be set for each analysis Method Operator name Sample name Sample quantity g o ml Notes INTERFACES N 2 USB for printer USB pen drive mouse 244 ...

Page 58: ...Velp Scientifica UDK139 Operating Manual 10004762 B5 58 13 Wiring diagram 245 ...

Page 59: ...ovalve 11 Distillation residues discharge electrovalve 12 Water inlet electrovalve 13 Electronic board for warning signals 14 Display board 15 Electronic board for reserve signals 16 Water flow detector 17 Safety microswitch for safety guard 18 Safety lever 19 Safety microswitch for test tube 20 Main board 21 Sodium hydroxide pump 22 Dilution water pump 23 Steam power pump 24 Cable 2 pole 25 Cable...

Page 60: ...Velp Scientifica UDK139 Operating Manual 10004762 B5 60 14 Hydraulic scheme 247 ...

Page 61: ...Velp Scientifica UDK139 Operating Manual 10004762 B5 61 EPDM Butyl MQ MVQ Silicone PTFE Teflon LLDPE Low density polyethylene 248 ...

Page 62: ... rendered faulty due to inexpert handling use or carelessness will not be replaced or repaired under warranty For more details please contact your Distributor Exclusions The guarantee will be considered null and void for faults resulting from inexperience and carelessness of the operator repairs maintenance or replacement of parts carried out by personnel or Companies not authorized by the manufac...

Page 63: ... 100 ml and therefore can be useful to use less diluted solutions For example bringing the indicated amounts to 100 ml instead of 1000 ml one obtains a final content of 0 1 mg N NH3 per ml of standard solution When the control of oxidative digestion is also required pure Nitrogen containing chemicals are used previously desiccated to constant weight Glycine glycocoll or aminoacetic acid 18 66 Nitr...

Page 64: ...dic vessel cation exchange resing mixed with a strongly basic anion exchange resin Sample to be analyzed Liquid semisolid or solid samples can be submitted to analysis If a liquid is measured by volume the result will be referred to volume and not to weight if the density is different from 1 When the result is to be referred to dry weight solid or semisolid samples containing water must be desicca...

Page 65: ...act with a sample can give rise to explosions Digestion temperatures and times Normal digestion temperature is 420 C Lower temperatures increase digestion time At 420 C digestion is completed in 20 45 minutes A completed digestion gives raise to a clear colourless solution that crystallizes on cooling If this crystallization is not wanted it is enough to lower a little the amount of the salt added...

Page 66: ...g N 50 HCl and an end point of pH 4 7 The low dissociation of boric acid allows direct titration of alkali ammonia Colorimetric determination Besides titration ammonia nitrogen determination can be performed by colorimetric methods for example 1 Method 417 B Nesslerization or Method 417 C Phenate Standard Methods for the Examination of Water and Wastewater 16th Edition APHA AWWA WPCF Washington D ...

Page 67: ...one drop of Hydrogen peroxide solution H2O2 30 130 voll is added and boiling is continued for 10 minutes When digestion is finished the tubes are left to cool Cooling time can be shortened by blowing air with a fan When the tubes are cool 50 ml of ammonia free distilled water are added and the tubes are shaken NOTE It s strongly recommended NOT to introduce in the test tubes during sample digestio...

Page 68: ...ndle with heat shields code A00001110 suction cup code A00109626 support system code A00001206 necessary accessories for DK 42 26 glassware handle with heat shields code A00001109 suction cup code A00109326 support system code A00001204 JP pump code F30620198 When using DK 42 26 digester Velp suggests to use 2 JP for the connection refer to the below scheme in order to guarantee an effective fumes...

Page 69: ...mount of reagents above if the sample is 7mg except when using the weighing boats 3 Digestion heat at 420 C for 1 hour 1 hour and a half 4 Cooling cool down test tubes to 50 60 C 5 Distillation place in position in the distilling unit the digested sample Program Select a method with the following volumes of the reagents dilution water 10 ml Boric acid 25 ml Sodium hydroxide 35 W V 10 ml Steam 100 ...

Page 70: ...nsfer quantitatively the measured sample to digestion tube D Add digestion acid and salts E Add catalysers if not present in the acid F Place the digestion tube in the digestion unit i e DK6 or DK20 G Digest the samples H Cool the digestion tubes I Place a digestion tube with sample in UDK 139 unit L Start the programmed automatic distillation cycle M Titrate distillate N Compute the results 257 ...

Page 71: ... mouldy surface layer of the cheese Homogenize the cheese manually with a spoon or a knife Weigh 1 000 g of sample into a nitrogen free weighing boat code CM0486000 and place it the test tube 2 Reagents for digestion a_ For milk sample add in the test tube 2 catalyst tablets CM code CT0006650 20 ml concentrated sulphuric acid 96 98 5 ml hydrogen peroxide H2O2 35 130 voll b_ For cheese sample add i...

Page 72: ...e CT0006650 12 ml concentrated sulphuric acid 96 98 2 antifoam tablets S code CT0006600 shake gently the test tubes 3 Digestion 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 Factor 5 18 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2 N Distillation tim...

Page 73: ...6650 12 ml concentrated sulphuric acid 96 98 2 antifoam tablets S code CT0006600 shake gently the test tubes 3 Digestion 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 factor 5 30 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time 4 min ...

Page 74: ...de CT0006650 12 ml concentrated sulphuric acid 96 98 2 antifoam tablets S code CT0006600 shake gently the test tube 3 Digestion 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 factor 5 46 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time...

Page 75: ...n for each sample add in the test tube 2 catalyst tablets ST code CT0006609 10 ml concentrated sulphuric acid 96 98 10 ml hydrogen peroxide H2O2 35 130 voll 2 antifoam tablets S code CT0006600 3 Digestion mix well the test tube content Heat for 30 min at 100 C 30 min at 200 C 30 min at 300 C and then for 40 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in...

Page 76: ...talyst tablets ST code CT0006609 12ml sulphuric acid concentrated 96 3 Digestion set on the digester the following temperature ramps 20 min at 220 C and then 40 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 factor 6 25 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titr...

Page 77: ...ts for digestion for each sample add in the test tube 1 catalyst tablet W code CT0006613 12 ml concentrated sulphuric acid 96 98 96 5 ml hydrogen peroxide H2O2 35 130 voll 3 Digestion heat for 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK139 factor 6 25 Addition of reagents dilution wat...

Page 78: ...t tube 2 catalyst tablets CM code CT0006650 2 Antifoam tablets S code CT0006600 12 ml concentrated sulphuric acid 96 98 shake gently the test tubes 3 Digestion heat for 40 min at 300 C and 90 minutes at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 factor 5 70 Addition of reagents dilution wa...

Page 79: ...the test tube 2 catalyst tablets CM code CT0006650 2 Antifoam tablets S code CT0006600 12 ml concentrated sulphuric acid 96 98 shake gently the test tubes 3 Digestion heat for 40 min at 300 C and 90 minutes at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 factor 6 25 Addition of reagents dilu...

Page 80: ...gestion for each sample add in the test tube 2 catalyst tablets CM code CT0006650 12 ml concentrated sulphuric acid 96 98 shake gently the test tubes 3 Digestion heat for 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 25 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 5...

Page 81: ...Reagents for digestion for each sample add in the test tube 2 catalyst tablets CM code CT0006650 15 ml concentrated sulphuric acid 96 98 shake gently the test tubes 3 Digestion heat for 70 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 25 Addition of reagents dilution water 50ml H3...

Page 82: ... add in the test tube 2 catalyst tablets ST code CT0006609 12 ml concentrated sulphuric acid 96 98 shake gently the test tubes 3 Digestion heat for 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 factor 6 25 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 ...

Page 83: ...ode CT0006650 15 ml sulphuric acid concentrated H2SO4 shake gently the test tube with the sample 3 Digestion heat for 75 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 25 Addition of reagents dilution water 75ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time 4 min Steam p...

Page 84: ...itatively transferred in the test tube 2 Reagents for digestion for each sample add in the test tube one of the following catalysts 2 catalyst tablets ST code CT0006609 20 ml concentrated sulphuric acid 96 98 5 ml hydrogen peroxide H2O2 35 130 voll 3 Digestion heat for 30 min at 250 C 30 min at 350 C 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place the te...

Page 85: ...lets TCT code CT0006621 12 ml concentrated sulphuric acid 96 98 shake gently the test tube with the sample 3 Digestion heat for 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 5 7 Reagents addition dilution water 75ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time 4 min S...

Page 86: ... tube 2 catalyst tablets CM code CT0006650 12 ml concentrated sulphuric acid 96 98 shake gently the test tube with sample 3 Digestion heat for 70 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 25 Reagents addition dilution water 75ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillat...

Page 87: ...huric acid 96 98 shake gently the test tube with sample For samples having high fat content use 15ml of acid and then 5ml of hydrogen peroxide 3 Digestion heat for 45 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with sample in the unit UDK 139 factor 6 25 reagents addition dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 ...

Page 88: ...s CM code CT0006650 12 ml concentrated sulphuric acid 96 98 shake gently the test tube with sample 3 Digestion heat for 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 25 Reagents addition dilution water 75ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time 4 min Steam po...

Page 89: ... for each sample add in the test tube 2 catalyst tablets CM code CT0006650 12 ml concentrated sulphuric acid 96 98 shake gently the tube with sample 3 Digestion heat for 60 min at 420 C 4 Cooling let cool test tubes to 50 60 C 5 Distillation titration place in position the tube with digested sample in the unit UDK 139 factor 5 7 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titran...

Page 90: ...each sample add in the test tube 2 catalyst tablets CM code CT0006650 12 ml concentrated sulphuric acid 96 98 shake gently the tube with sample 3 Digestion heat for 60 min at 420 C 4 Cooling let cool test tubes to 50 60 C 5 Distillation titration place in position the test tube with sample in the unit UDK 139 factor 6 25 Reagents addition dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 1N ...

Page 91: ...blets ST code CT0006609 13 ml concentrated sulphuric acid 96 98 shake gently the tube with the sample 3 Digestion heat for 60 min at 420 C 4 Cooling let cool test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 25 Reagents addition dilution water 75ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time 4 min Steam pow...

Page 92: ... code CT0006609 15 ml concentrated sulphuric acid 96 98 shake gently the tube with the sample 3 Digestion heat for 60 min at 420 C 4 Cooling let cool the tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 25 Reagents addition dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time 4 min Steam power 100 Pr...

Page 93: ...c acid 96 98 add carefully 10ml of hydrogen peroxide to avoid foaming Shake gently the test tube with sample 3 Digestion start from room temperature and use heating ramps up to 420 C overall time 4 hours Maintain at 420 C for 30 min Overall digestion time 4 hours and 30 min 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sampl...

Page 94: ... 2 catalyst tablets CM code CT0006650 2 Antifoam tablets S code CT0006600 15 ml concentrated sulphuric acid 96 98 5 ml Hydrogen peroxide 30 32 added 1 by 1 ml after the addition of reagents shake to wet the sample In some cases it could be necessary to pre digest the samples overnight at room temperature 3 Digestion 30 min at 250 C 30 min at 350 C 60 min at 420 C 4 Cooling let cool the test tubes ...

Page 95: ... CT0006650 12ml concentrated sulphuric acid 96 98 after the addition of reagents shake to wet the sample 3 Digestion 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 0 00 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant HCl 0 2N Distillation time 4 min Steam po...

Page 96: ...ater 0 1 0 5 mg of nitrogen in most cases in a standard test tube With DKL12 it is possible to use the Jumbo test tube 400 ml code A00000185 with the dedicated sample rack code A00000181 2 Reagents for digestion for each sample add in the test tube 2 catalyst tablets CM code CT0006650 10 ml concentrated sulphuric acid 96 98 3 Digestion mix well the test tube content Heat for 30 min at 150 C 30 min...

Page 97: ...ly weighed and quantitatively transferred in a test tube 2 Reagents for digestion 2 catalyst tablets ST code CT0006609 12 ml concentrated sulphuric acid 96 98 3 Digestion heat for 60 min at 420 C 4 Cooling let cool the test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 0 00 Addition of reagents dilution water 50 ml H3BO3 3...

Page 98: ...ode CT0006609 15 ml concentrated sulphuric acid 96 98 3 Digestion Heat at 200 C for some minutes to let the foam develop then go to 420 C for 30 minutes 4 Cooling Let cool test tubes to 50 60 C 5 Distillation titration place in position the test tube with the digested sample in the unit UDK 139 factor 5 60 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant H2SO4 0 1 N Distillat...

Page 99: ...06609 15 ml concentrated sulphuric acid 96 98 3 Digestion Heat at 200 C for some minutes to let the foam develop then increase the temperature to 420 C for 30 minutes 4 Cooling Let cool test tubes to 50 60 C 5 Distillation titration place in position the test tube with digested sample in the unit UDK 139 factor 6 30 Addition of reagents dilution water 50ml H3BO3 30ml NaOH 50 ml Titrant H2SO4 0 1 N...

Page 100: ...eam distilled and titrated Procedure 1 Sample about 0 5 g of sludge dried at 105 C up to constant weight 10 20 mg of N or a corresponding amount of wet sludge accurately weighed and quantitatively transferred in a test tube 2 Reagents for the reduction for each sample add in the test tube 0 5 g chromium powder Cr 20 ml hydrochloric acid 7 about HCl 200 ml of concentrated acid 36 to 1 liter by ammo...

Page 101: ...es Bring the volume of the sample to the mark exactly 200 ml by taking away excess sample by a small pipette Transfer the wine to the 1 liter test tube Rinse the graduated flask four times with successive 5 ml washings of water added to the test tube Then add 10 ml of the suspension of calcium hydroxide The color of the wine must change for example from red to deep grey For very acid wines it s su...

Page 102: ...ensity of the distillate at 20 C Ddist 20 C following the formula Ddist 20 C Mdist Mpyc Vpyc x 1000 Vpyc m3 is the volume of the empty pycnometer and is calculated as follows Vpyc Mpyc H2O Mpyc ρH2O 20 C x 1000 Where Mpyc H2O pycnometer weight filled with water at 20 C g ρH2O 20 C density of the water at 20 C 0 99823 g ml 4 Use the density table of the official method to express the results for wi...

Page 103: ...e and bring to 30 C water bath Allow the enzymatic reaction develop for 60 min shaking at intervals 3 Distillation analytical parameters H2O 0ml H3BO3 0 ml NaOH 0 ml Distillation time 4 min Steam power 100 Introduce 30 0 ml of titrated 0 1 N solution of hydrochloric acid in the Erlenmeyer flask used to collect the distillate place it in position with the tip of the silicone tube dipped in the acid...

Page 104: ... N and methyl red indicator The solutions cannot be stored The determination of the enzymatic activity is performed by adding increasing known volumes of neutralized urease solution to 0 1 g of pure urea After 1 hour incubation at room temperature ammonia is steam distilled It is to be used the volume of urease solution which frees completely ammonia from 0 1g of urea during 1 hour 3 Incubation 2 ...

Page 105: ... of sample by the VELP weighing boats and introduce in the test tube The use of the weighing boats avoids errors during the sample weighing permitting to transfer completely the sample to the test tube for the analysis As an alternative the following amount of sample can be used 600 R g weighed with a tolerance margin of 0 01g R is the content of NTSS natural total soluble solids or soluble dry ma...

Page 106: ... of sample 0 6 x ml NaOH 0 1N g of sample NOTE at the end of the analyses perform 3 washing cycles of the distillator Introduce in the test tube 150 200ml of distilled or deionised water and set for each washing cycle 5 min for the distillation time The aim is the complete removal of traces of sample from the glass splash head References Commission Reg EEC No 1764 86 Minimum quality requirements f...

Page 107: ...lution 0 005M of iodine I2 analytical purity crystallised potassium iodide KI analytical purity starch water 5g l dissolve 5g of starch in about 500ml of water Bring to boiling stir and maintain 10 minutes add 200g of sodium chloride After cooling down bring the volume to 1l saturated solution of sodium tetra borate Na2B4O7 10 H2O analytical purity about 55g l at 20 C Procedure 1 Sample preparatio...

Page 108: ...ents or to 0 053g of acetic acid knowing the amount of sorbic acid mg l determined separately 6 Determination of the salycilic acid present in the distillate of the volatile acidity After the determination of the volatile acidity and after the correction for the sulphur dioxide the presence of salycilic acid is revealed after the addition of acid by the presence of a violet colour forming after ad...

Page 109: ... the flask will turn violet Pour in a flask equal to the flask with the level mark some distilled water up to the same distillate level Add 0 3ml of hydrochloric acid and 1ml of solution of ammonic ferric sulphate Add by a burette the solution of sodium salycilate 0 01M until a violet colour is obtained having the same intensity of the colour in the flask containing the wine distillate Being n the...

Page 110: ...ours Procedure 1 Sample 1 1 5 g of homogeneous sample weighed with a proximation of 0 1 mg It s suggested to use nitrogen free weighing boats Cod Art CM0486000 CM0486001 It s suggested furthermore to introduce the boat in the test tube immediately after weighing to avoid the raise of oil by capillarity along the folded sides of the boat The sample containing boat is slipped along the side of the d...

Page 111: ...he following analytical parameters Factor 0 00 Addition of reagents H2O 70 ml H3BO3 30 ml NaOH 50 ml Titrant HCl or H2SO4 0 1 N Distillation time 4 min Steam power 100 Push START to start the analysis References American Society for Testing and Materials Standard Test Method D 3228 96 Total Nitrogen in Lubricating Oils and Fuel Oils by Modified Kjeldahl Method 298 ...

Page 112: ...ubtracted the amount of ammonia nitrogen and nitrite nitrogen present in the sample determined separately to obtain nitrate nitrogen in the sample Procedure 1 Sample 50 ml of water or between 20 and 70 ml depending on the nitrate content accurately measured and introduced in a test tube 2 Reagent for the reduction of nitrates and nitrites to ammonia for each sample 2 g Devarda s alloy powder 3 Red...

Page 113: ...distillation Procedure 1 Sample 50 ml of water or between 20 and 70 ml depending on ammonia nitrogen content accurately measured and introduced in the test tube 2 Reagents the sample to be distilled must be alkalinized indicator phenolphthalein with alkali or simply adding 1 2 g magnesium oxide MgO A saturated solution of magnesium oxide shows pH 10 3 3 Distillation e titration Set the following a...

Page 114: ...sly boiled and cooled Type II Aminoantipyrine solution dissolve 2 g of 4 aminoantipyrine in 100 ml of distilled water Potassium ferricyanide solution dissolve 8 g of K3Fe CN 6 in 100 ml of distilled water Ammonium chloride solution 2 dissolve 20 g of NH4Cl in 1000 ml of distilled water Ammonia 25 Concentrated phenol solution 1000 mg l dissolve 250 mg of phenol in 250 ml of freshly boiled and coole...

Page 115: ...f potassium ferricyanide solution Shake the separatory funnel and after 5 minutes add 25 ml of chloroform with a pipette Shake vigorously for about 2 minutes and let the organic phase settles Filter chloroform extract through a filter paper and collect the filtrate in a 100 ml flask Transfer the filtrate solution in a 50 mm glass cuvette and read the extinction values at 460 nm against distilled w...

Page 116: ...trated d 1 84 Mercury chloride HgCl2 68 g l in water Magnesium chloride hexahydrate MgCl2 6H2O 510 g l in water Silver nitrate AgNO3 dried at 140 C 3 2467 g l in water 0 0192 N Rhodanine indicator 0 02 g 100 ml in acetone 3 Pre treatment of the sample before distillation Sulphides are removed at pH 11 by adding lead carbonate powder up to a complete precipitation of lead sulphide which is removed ...

Page 117: ...into the flask and titrate by silver nitrate The concentration of cyanides can be calculated as follows CN µg L A B D 2 mole CN 26 02 g CN 1 106 µg C 1 eq AgNO3 1 mole CN 1 g A ml AgNO3 for titration of sample B ml AgNO3 for titration of blank C ml of original sample before distillation 200 ml recommended D actual normality of AgNO3 0 0192 N recommended References ENVIRONMENTAL PROTECTION AGENCY T...

Page 118: ...alein indicator 0 5 g in 100 ml of distilled water Methyl orange indicator solution 0 05 g in 100 ml of distilled water Acetic acid CH3COOH 2000 mg l Dilute 1 9 ml glacial acetic acid to 1000 ml by deionized or distilled water Titrate by sodium hydroxide 0 04 N 10 ml of the solution 0 33 meq require 8 3 ml of sodium hydroxide 0 04 N phenolphthalein indicator 2 Sample 150 200 ml of digesting slurry...

Page 119: ...ml 6005x1000 x N x NaOH ml used F represents a recovery factor of the distillator used which is obtained by distilling known volumes eg 10 ml of acetic acid solution 2000 mg l and computing l theoretica NaOH ml 100 x used NaOH ml factor References Lombardo J B 1973 Improved distillation method for volatile acid analysis Journal Water Pollution Control Federation 45 1046 1051 Buswell A M 1945 A not...

Page 120: ...of 0 1 mg and quantitatively transferred in a test tube 2 Distillation and titration the sample to be distilled must be alkalized phenolpthalein indicator by adding 2g or a higher quantity of Magnesium oxide MgO free from carbonates Place the test tube containing the alkalized sample in the UDK 139 unit Select the following analytical parameters Factor 0 00 Addition of reagents H2O 50 ml H3BO3 30 ...

Page 121: ...ontrol indicates that the limit for TVBN 25 30 35 mg 100g depending on the species of fish has been exceeded The described method is suitable also for meat analysis Procedure 1 Sample prepare a representative sample by a suitable homogenizer Bigger skin and bone pieces should be removed before homogenization The sample must be analysed within 4 hours from the preparation If not analysed immediatel...

Page 122: ...factured in conformity with the following standards EN 61010 1 2001 EN 61010 2 010 2003 EN 61010 2 081 2003 EN 61326 1 2006 and satisfies the essential requirements of the following directives 2006 42 EC 2006 95 EC 2004 108 EC 2011 65 UE RoHS 2012 19 UE RAEE plus modifications and that the documents listed in annex I are available at Velp s offices as foreseen by the machinery directive 309 ...

Page 123: ...t Lines Environment Thermoreactors ECO series B O D Determination systems Refrigerated thermostats Cooled Incubators Flocculators Overhead mixer Mineralization system for heavy metals trace determination Turbidimeter Radiation Detector Stirring Heating magnetic stirrers Vertex digital thermoregulator Ultraflat magnetic stirrer Magnetic stirrers Overhead stirrers Heating plates Vortex mixers Homoge...

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