Does Hach have a tolytraizole standard to check the accuracy of Method 8079?

Document ID

Document ID TE1477

Version

Version 2.0

Status

Status Published

Published Date

Published Date 27/05/2017
Question
Does Hach have a tolytraizole standard to check the accuracy of Method 8079?
Summary
Tolytraizole standard
Answer
Hach does not carry a tolytriazole standard, but does carry Benzotriazole Standard Solution, 500 mg/L, 100 mL (catalog number 2141342). The molecular weight of tolytriazole is 133.15 g/mol and the molecular weight of benzotriazole is 119.13 g/mol. Therefore, theoretically the conversion factor from benzotriazole to tolytriazole is then 1.118. However, the two compounds are measured on separate curves for Hach spectrophotometers. The calibration curves are not necessarily linear so there is not a single factor that can be used to compare between the two curves. Using the benzotriazole standard on both programs and obtaining accuracy close to a factor of 1.118-1.2, would be considered a passing test in the tolytriazole program.