How is a Lachat Cadmium Column for Nitrate determination checked for efficiency?

Document ID

Document ID TE6360

Version

Version 2.0

Status

Status Published

Published Date

Published Date 27/05/2017
Question
How is a Lachat Cadmium Column for Nitrate determination checked for efficiency?
Summary
Procedure to check cadmium column efficiency
Answer
Column, Cadmium, for Nitrate determination  (Catalog Number/Order Code 50237A)

Column Efficiency
Before running samples, column efficiency can be determined as follows:
 
1. Calibrate with nitrate (NO 3 ) standards.
 
2. Run a known concentration of nitrite (NO 2 ) standard as N.
 
3. Run a matching concentration of NO 3 standard as N.
 
The column efficiency is determined by the equation:
 

 
where:
 
E = column efficiency
[NO 3 ] = concentration of nitrate standard
[NO 2 ] = concentration of nitrite standard
If the efficiency is less than 90%, do not use the cadmium column. Contact Lachat
technical support or the local distributor.