Hach DR/850, Procedures Manual, Page: 3 / 460

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TABLE OF CONTENTS
INTRODUCTION..................................................................................................................... 7
Sample Procedure Explained ....................................................................................................9
SECTION 1 CHEMICAL ANALYSIS INFORMATION ...................................................... 13
Abbreviations ......................................................................................................................... 13
Converting Chemical Species ................................................................................................ 14
Hardness Conversion ....................................................................................................... 15
Dissolved Oxygen............................................................................................................ 16
Sample Collection, Preservation and Storage.................................................................. 18
Correcting for Volume Additions .................................................................................... 22
Boiling Aids..................................................................................................................... 23
Sample Filtration ............................................................................................................. 23
Temperature Considerations ............................................................................................ 25
Sample Dilution Techniques............................................................................................ 25
Using Pipets and Graduated Cylinders ............................................................................ 26
Using the TenSette Pipet.................................................................................................. 28
Mixing Water Samples .................................................................................................... 29
Using Sample Cells.......................................................................................................... 31
Using AccuVac Ampuls................................................................................................... 32
Using Reagent Powder Pillows ....................................................................................... 33
Using PermaChem Pillows .............................................................................................. 33
Reagent and Standard Stability........................................................................................ 34
Interferences ........................................................................................................................... 34
pH Interference ................................................................................................................ 35
Accuracy and Precision .......................................................................................................... 36
Standard Additions .......................................................................................................... 36
Method Performance .............................................................................................................. 43
Estimated Detection Limit............................................................................................... 43
Precision .......................................................................................................................... 46
Reagent Blank Correction ...................................................................................................... 47
Standard Adjust (Adjusting the Standard Curve)................................................................... 47
Preparing a User-Entered Calibration Curve ................................................................... 49
USEPA Approved and Accepted Definitions......................................................................... 51
SECTION 2 SAMPLE PRETREATMENT ............................................................................ 53
Digestion ................................................................................................................................ 53
EPA Mild Digestion with Hot Plate for Metals Analysis Only ....................................... 53
EPA Vigorous Digestion with Hot Plate for Metals Analysis Only ................................ 54
General Digesdahl Digestion (Not USEPA accepted) ..................................................... 55