What could be the cause of a precipitate when using the CuVer® 1 chemistry in a sample with hard water?

Document ID

Document ID TE259

Version

Version 2.0

Status

Status Published

Published Date

Published Date 27/05/2017
Question
What could be the cause of a precipitate when using the CuVer® 1 chemistry in a sample with hard water?
Summary
Precipitate forms when using CuVer1® chemistry
Answer
The phosphate buffer in the CuVer® 1 reagent combines with the calcium in the hardness to form an insoluble calcium phosphate which can precipitate. To treat this add several drops of Rochelle Salt solution catalog number 172533 to the sample before adding the CuVer® 1 chemistry or switch to CuVer® 2 which does not contain the phosphate buffer.