manualshive.com logo in svg

Thermo Electron Orion 95-02, Инструкция по эксплуатации

Поделиться
Скачать
Thermo Electron Orion 95-02 Скачать руководство пользователя страница 15

13

Known Addition

Known Addition is a convenient technique for measuring samples
because no calibration curve is needed.  It can be used to verify the
results of a direct calibration or to measure the total concentration of
an ion in the presence of a large excess of a complexing agent.  The
sample potential is measured before and after addition of a standard
solution.  Accurate measurement requires that the following
conditions be met.

- Concentration should approximately double as a result of 

the addition.

- Sample concentration should be known to within a 

factor of three.

- In general, either no complexing agent or a large excess of the 

complexing agent may be present.

- The ratio of the uncomplexed ion to complexed ion must not be 

changed by addition of the standard.

- All samples and standards should be at the same temperature.

Set up

1. Connect electrodes to the meter.

2. Prepare a standard solution which, upon addition to the sample, 

will cause the concentration of the carbon dioxide to double.  
Refer to 

Table 2

as a guideline.

3. Determine the slope of the electrode by performing the 

procedure under Checking Electrode Operation (Slope).

4. Rinse electrode between solutions with distilled water.

Table 2

Volume of Addition 

Concentration of Standard

1 mL

100 x sample concentration

5 mL 

20 x sample concentration

10 mL*

10 x sample concentration

*Most convenient volume to use.

Содержание Orion 95-02

Страница 1: ...Analyze Detect Measure Control Orion 95 02 Orion Carbon Dioxide Electrode INSTRUCTION MANUAL CO2 ...

Страница 2: ...tat Face The Enhanced Lab ThermaSense Triode TRIUMpH Unbreakable pH Universal Access are trademarks of Thermo Guaranteed Success and The Technical Edge are service marks of Thermo PerpHecT meters are protected by U S patent 6 168 707 PerpHecT ROSS are protected by U S patent 6 168 707 ORION Series A meters and 900A printer are protected by U S patents 5 108 578 5 198 093 and German patents D334 20...

Страница 3: ...orage 8 Measuring Hints 8 Analytical Procedures 10 Analytical Techniques 10 Direct Calibration 10 Known Addition 13 Electrode Storage 17 TROUBLESHOOTING 18 Troubleshooting Checklist 18 Troubleshooting Guide 22 Assistance 24 ELECTRODE CHARACTERISTICS 25 Electrode Response 25 Reproducibility 25 Temperature Effects 25 Interferences 26 Effects of Dissolved Species 26 Theory of Operation 28 ACCESSORIES...

Страница 4: ...2 Tweezers Carbon Dioxide Electrode box of four with two O rings Membrane Spacer Assemblies Figure 1 Contents Of Storage Box Flip top Spout Internal Filling Solution 50 mL bottle ...

Страница 5: ...l meter s instruction manual Our Technical Service Chemists can be consulted for assistance and troubleshooting advice Please refer to TROUBLESHOOTING for information on contacting Orion Required Equipment Meter The easiest to use are direct concentration readout meters such as Orion EA 940 920A 720A 710A or 290A If unavailable a pH mV meter with readability to 0 1mV such as Orion 520A or 420A is ...

Страница 6: ...To fill the electrode For inner body check pH 4 01 Buffer with 0 1 M NaCl added for checking inner body operation Use Orion Buffer Orion No 910104 or prepare 200 mL pH 4 00 buffer from Orion Buffer Powder Orion No 910004 Add 1 16 g reagent grade NaCl to 100 mL of the buffer solution Dissolve solid and store the buffer for repeated use Discard buffer if turbidity develops pH 7 00 Buffer with 0 1 M ...

Страница 7: ...e TROUBLESHOOTING top cap vent hole outer body bottom cap 1 Remove top cap Lift out inner body Pour out old internal filling solution Remove bottom cap 5 Fill outer body with internal filling solution 6 Put inner body into outer body Screw top cap on Excess will vent Figure 2 Electrode Assembly and Preparation 2 Remove O ring and old membrane assembly from cap 3 Place membrane spacer assembly in t...

Страница 8: ...as sensing electrodes are placed in the electrode holder so that they are at a 20 angle from the vertical This avoids trapping air bubbles at the tip of the electrode 2 Place 45 mL distilled water and 5 mL carbon dioxide buffer into a 100 mL beaker Stir thoroughly Set the function switch of the meter to the mV mode 3 Rinse electrode with distilled water and place in the solution prepared in step 2...

Страница 9: ...es carbon dioxide buffer solutions must be added to samples and standards before measurement After addition of the buffer solution all samples and standards should fall within the pH 4 8 to 5 2 range so that all bicarbonate and carbonate is converted to carbon dioxide and so that possible interferences are minimized Since the buffering capacity of the acid buffer is limited highly basic highly aci...

Страница 10: ... NaOH should not be used to store samples containing less than 100 ppm CO2 since carbonate is usually collected in a stoppered glass bottle Fill the bottle completely and cap tightly to prevent loss of CO2 Measuring Hints Minimize CO2 loss from samples by Measuring samples as soon as possible after collection Storing samples according to Sample Storage Minimizing the ratio of surface area to volum...

Страница 11: ...old change Always rinse electrodes with distilled water between measurements see Electrode Preparation Shake after rinsing to prevent solution carry over Blot dry Do not wipe or rub the sensing membrane Allow all standards and samples to come to room temperature for precise measurement After immersion in solution check electrode for any air bubbles on membrane surface and remove ...

Страница 12: ...f a specific ion in the presence of a large 50 100 times excess of complexing agents Known Addition is an alternate method useful for measuring dilute samples checking the results of direct calibration when no complexing agents are present or measuring the total concentration of an ion in the presence of an excess complexing agent The electrodes are immersed in the sample solution and an aliquot o...

Страница 13: ...ed in the meter instruction manual 3 Measure 50 mL of the more concentrated standard into a second 150 mL beaker Add 5 mL carbon dioxide buffer Stir thoroughly 4 Rinse electrodes with distilled water blot dry and place into the beaker with more concentrated standard Wait for a stable read ing then adjust the meter to display the value of the second standard as described in the meter instruction ma...

Страница 14: ...thoroughly 5 Rinse electrodes with distilled water blot dry and place into the second beaker When a stable reading is displayed record the mV value and corresponding standard concentration 6 Using semilogarithmic graph paper prepare a calibration curve by plotting the millivolt values on the linear axis and the standard concentration values on the logarithmic axis 7 Measure 50 mL of the sample int...

Страница 15: ...either no complexing agent or a large excess of the complexing agent may be present The ratio of the uncomplexed ion to complexed ion must not be changed by addition of the standard All samples and standards should be at the same temperature Set up 1 Connect electrodes to the meter 2 Prepare a standard solution which upon addition to the sample will cause the concentration of the carbon dioxide to...

Страница 16: ...7 0 1706 0 1734 9 6 0 1614 0 1642 0 1671 0 1698 9 8 0 1581 0 1609 0 1636 0 1664 10 0 0 1548 0 1576 0 1603 0 1631 10 2 0 1517 0 1544 0 1571 0 1598 10 4 0 1487 0 1514 0 1540 0 1567 10 6 0 1458 0 1484 0 1510 0 1537 10 8 0 1429 0 1455 0 1481 0 1507 11 0 0 1402 0 1427 0 1453 0 1479 11 2 0 1375 0 1400 0 1426 0 1451 11 4 0 1349 0 1374 0 1399 0 1424 11 6 0 1324 0 1349 0 1373 0 1398 11 8 0 1299 0 1324 0 13...

Страница 17: ... 0 0405 0 0416 30 0 0 0373 0 0383 0 0394 0 0405 31 0 0 0353 0 0363 0 0373 0 0384 32 0 0 0334 0 0344 0 0354 0 0364 33 0 0 0317 0 0326 0 0336 0 0346 34 0 0 0300 0 0310 0 0319 0 0328 35 0 0 0285 0 0294 0 0303 0 0312 36 0 0 0271 0 0280 0 0288 0 0297 37 0 0 0257 0 0266 0 0274 0 0283 38 0 0 0245 0 0253 0 0261 0 0269 39 0 0 0233 0 0241 0 0249 0 0257 40 0 0 0222 0 0229 0 0237 0 0245 41 0 0 0211 0 0218 0 0...

Страница 18: ...s displayed record the sample concentration Analysis using a meter with millivolt readout only Use this procedure when no instructions for known addition are available in the meter instruction manual 1 Set the meter to relative millivolt mode 2 Measure 50 mL of the sample into a 100 mL beaker Add 5 mL carbon dioxide buffer Stir thoroughly 3 Rinse electrodes with distilled water blot dry and place ...

Страница 19: ... 2 to 60 1 mV decade The equation for the calculation of Q for different slopes and volume changes is given below p Q 1 p 10 E S 1 where Q reading from known addition table E E2 E1 S slope of the electrode volume of standard p volume of sample Electrode Storage To store the electrode between samples overnight or over a weekend immerse the electrode tip in a 0 1M NaCl storage solution If the electr...

Страница 20: ...ternal filling solution readings erratic rapidly changing Defective meter Bottom cap loose Defective inner body Carbon dioxide buffer not used Meter stirrer improperly grounded Drift reading Internal filling solution leakage slowly changing in one direction Incorrect internal filling solution Total level of dissolved species above 1M Electrode in sample too long CO2 loss Membrane failure wet perfo...

Страница 21: ... meter instruction manual Ensure that bottom cap is screwed on tight enough to close gap between bottom cap and body Check inner body operation Use recommended carbon dioxide buffer Orion No 950210 Check meter and stirrer for grounding Ensure that membrane is installed properly Refill outer body of electrode using filling solution shipped with electrode Orion No 950202 Dilute solution Reduce surfa...

Страница 22: ...ures Low slope or Standards contaminated or No slope incorrectly made CO2 buffer not used Standard used as CO2 buffer Electrode exposed to air Membrane failure wet perforation discoloration Defective inner body Wrong Answer Incorrect scaling of But calibration semilog paper curve is OK Incorrect sign Incorrect standards Wrong units used CO2 buffer added to standards and not samples ...

Страница 23: ...electrode by outer body and pull up on electrode for extended period cable Internal filling solution will flow under membrane and restore electrode response Replace membrane Check inner body operation Plot millivolts on the linear axis On the log axis be sure concentration numbers within each decade are increasing with increasing concentration Be sure to note sign of millivolt value correctly Prep...

Страница 24: ...er body Disassemble the electrode If the electrode is dry first soak the glass tip of the inner body in filling solution for at least 2 hours Rinse the inner body with distilled water and immerse it in the pH 7 buffer with 0 1M CL added so that the reference element is covered Stir throughout the procedure Record electrode potential in millivolts Rinse the inner body in distilled water and place i...

Страница 25: ... to prepare a third standard and so on until the desired range of standards has been prepared Sample If the electrodes work properly in standards but not in samples look for possible interferences complexing agents or substances which could affect response or physically damage the sensing electrode or the reference electrode If possible determine the composition of the samples and check for proble...

Страница 26: ...t The Technical EdgeSM for Orion products Within the United States call 1 800 225 1480 outside the United States call 978 232 6000 or fax 978 232 6031 In Europe the Middle East and Africa contact your local authorized dealer For the most current contact information visit www thermo com ...

Страница 27: ...ncentration should be diluted before measurement Figure 4 shows the time response of the carbon dioxide electrode to step changes in carbon dioxide concentration Reproducibility Reproducibility is limited by factors such as temperature fluctuations drift and noise Within the operating range of the electrode reproducibility is independent of concentration With calibration every hour electrode measu...

Страница 28: ...atures are the same Addition of carbon dioxide buffer to samples of low osmotic strength automatically adjusts them to the correct level Samples with osmotic strengths greater than 1 M should be diluted before measurement Dilution should not reduce the carbon dioxide level below 10 4 M Samples with osmotic strengths above 1 M that cannot be diluted can be measured by adjusting the osmotic strength...

Страница 29: ...5 X 10 M NaHCO 3 5 3 10 M to 10 M NaHCO 3 4 3 electrode potential mV 10 M to 10 M NaHCO 3 2 3 100 75 50 25 25 50 0 1 2 3 4 5 6 7 8 time minutes Figure 4 Typical Electrode Response To Step Changes in Carbon Dixoide ...

Страница 30: ...ctrode inner body located behind the membrane The relationship between carbon dioxide water bicarbonate and hydrogen ion is given by the following equation H HCO3 constant CO2 The internal filling solution contains a high level of sodium bicarbonate so that the bicarbonate level can be considered constant H CO2 constant The potential of the pH sensing element is related to the hydrogen ion concent...

Страница 31: ...O 2 3 pH Figure 6 Fraction of Carbonate Bicarbonate and Carbon Dixoide Ion As A Function Of pH Figure 5 Construction Of The Carbon Dixoide Electrode sensing element membrane spacer assembly bottom cap red O ring internal filling solution reference element outer body inner body ...

Страница 32: ...ectrode measurement The carbon dioxide buffer used in carbon dioxide determinations keeps the pH between 4 8 and 5 2 and converts the carbonate and bicarbonate to the CO2 form H HCO3 H2O CO2 2H CO3 H2O CO2 The electrode then can be used to measure the total amount of carbon dioxide in solution The concentration of carbon dioxide in solution is directly proportional to the partial pressure of carbo...

Страница 33: ... gauge large bore stainless steel tubing The sample is introduced into the measuring chamber by a syringe pump or peristaltic pump Recommended pumps include the Sage Orion 351 Syringe Pump and Orion 375A Peristaltic Pump manufactured by the Sage Instruments division of Orion The volume of the measuring chamber is about 0 1 mL To remove all traces of the previous sample 0 5 to 1 mL of sample must b...

Страница 34: ...d States and Canada Thermo reserves the right to ask for proof of purchase such as the original invoice or packing slip Field Service is available on Orion BOD AutoEZ EZ Flash GC Accessory and TEA Analyzer Contact our Field Service department for details on quotations service and other field service related activities The following products are warranted to be free from defects in material and wor...

Страница 35: ...ve Electrodes ionplus Electrodes ROSS Electrodes Sure Flow Electrodes PerpHecT Electrodes AquaPro Professional Electrodes No Cal pH electrodes Standard Line pH Electrodes Tris pH Electrodes KNIpHE electrode ORP Triode Orion 9180BN pHuture pH Probes Orion 616500 and pHuture MMS Quatrode and Triode Orion 616600 and 617900 Orion 97 08 DO Probe Series 100 Conventional Conductivity Cells temperature pr...

Страница 36: ...ement please visit our website at www thermo com THE WARRANTIES DESCRIBED ABOVE ARE EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES WHETHER STATUTORY EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AND ALL WARRANTIES ARISING FROM THE COURSE OF DEALING OR USAGE OF TRADE THE BUYER S SOLE AND EXCLUSIVE REMEDY IS FOR REPAIR OR R...

Страница 37: ...35 ...

Страница 38: ...No Description 950202 Internal Filling Solution 50 mL bottle 950204 Membranes box of four with two O rings 950206 Standard Solution 0 1 M NaHCO3 950207 Standard Solution NaHCO3 1000 ppm as CaCO3 950210 Carbon Dioxide Buffer Solution ...

Страница 39: ... to 10 4 M CO2 4 4 to 400 ppm CO2 pH Range 4 8 to 5 2 pH Temperature Range 0 to 50 C Electrode Resistance 1000 megohms Reproducibility 2 Sample Aqueous solutions only Size Electrode Length 151 mm Body Diameter 17 mm Cap Diameter 22 mm Cable 75 cm ...

Страница 40: ...38 NOTES ...

Страница 41: ...39 NOTES ...

Страница 42: ...40 NOTES ...

Страница 43: ... England CB6 2HY Tel 44 1353 666111 Fax 44 1353 666001 Far East Room 904 Federal Building 369 Lockhart Road Wanchai Hong Kong Tel 852 2836 0981 Fax 852 2834 5160 Customer Support Toll Free 800 225 1480 www thermo com Dom e mail domcs1 thermoorion com Int l e mail intcs1 thermoorion com For updated contact information visit www thermo com Analyze Detect Measure Control 228229 001 Rev E Powered by T...

Отзывы:

Нет отзывов

Бренды по названию

Популярные бренды

Загрузить еще бренды