Question
Why are the results using the BOD Standard Solution, 300 mg/L, pk/16 - 10-mL Voluette® Ampules twice the expected result?
Summary
BOD Standard Solution, 300 mg/L, pk/16 - 10-mL Voluette® Ampules preparation
Answer
The Standard Methods result of 198 +/- 30.5 mg/L BOD is based on standards containing 150 mg/L each of Glucose and Glutamic Acid (GGA). The BOD Standard Solution, 300 mg/L, pk/16 - 10-mL Voluette® Ampules (Product # 1486510) contains 300 mg/L each of Glucose and Glutamic acid (double the concentration listed in Standard Methods).
As a result, if 6 mL of the Hach BOD standard are used, the results will be twice as high (one can divide by the final result by 2, or use 3 mL of standard for comparison with Standard Methods).
For instructions on how to use the standard, please see the following article:
Are there instructions for using the BOD Standard Solution, 300 mg/L, pk/16 - 10-mL Voluette® Ampules?
As a result, if 6 mL of the Hach BOD standard are used, the results will be twice as high (one can divide by the final result by 2, or use 3 mL of standard for comparison with Standard Methods).
For instructions on how to use the standard, please see the following article:
Are there instructions for using the BOD Standard Solution, 300 mg/L, pk/16 - 10-mL Voluette® Ampules?