Analytical method for the determination of cadmium and its inorganic compounds

Translation of DGUV Information 213-554 (former BGI 505-54 or ZH1/120.54)

Method 03 – GFAAS

Sampling is performed by drawing a defined volume of air through a quartz fibre filter using a suitable flow-regulated pump

This analytical method is a validated measurement procedure for the determination of cadmium and cadmium compounds in workplace air after personal or stationary sampling.

Principle

A pump is used to draw a defined volume of air through a quartz fibre filter. After high-pressure microwave digestion, the respirable and inhalable fraction of cadmium retained on the filter is analysed using an atomic absorption spectrometer with the graphite furnace technique.

Limit of quantification (calculated as Cd)

Absolute: 1.8 pg of cadmium, 0.0023 µg of cadmium per sample carrier.

Relative: 0.0019 µg/m³ for an air sample volume of 1.2 m³ (a sampling period of 2 h at 10 L/min, a measurement solution volume of 25 mL and an injection volume of 20 µL).

Issue

August 2020 

The complete measuring method is available in the ZB Med: Cadmium – Method for the determination of cadmium and its compounds in workplace air using graphite furnace atomic absorption spectrometry (GF-AAS) after high-pressure microwave digestio (The MAK Collection for Occupational Health and Safety 2022, Volume 7, No. 4).

Method 02 – ICP-MS

Sampling is carried out with a pump and collection on a particulate filter. Analysis is performed by ICP mass spectrometry after acid digestion.

This analytical method describes the determination of the mean concentration of cadmium and its inorganic compounds in workplace air averaged over the sampling period after personal or stationary sampling.

Principle

A pump draws a defined volume of air through a nitrocellulose membrane filter. After unpressurised acid digestion, the aerosol captured on the collection phase is analysed by means of mass spectrometry with inductively coupled plasma (ICP-MS).

Limit of quantification (LOQ)

The limit of quantification is essentially influenced by the collection phase used.

a) Use of commercially available nitrocellulose membrane filters:

Absolute: 6 μg/L.

Relative: 0.5 μg/m³ at an air sample of 1.2 m³ (2 h of sampling at an intake rate of 10 L/min), 0.13 μg/m³ at an air sample of 4.8 m³ (8 h of sampling at an intake rate of 10 L/min) as well as a measuring solution of 20 mL and a dilution factor of 5.

b) Use of batch-tested nitrocellulose membrane filters:

Absolute: 0.1 μg/L.

Relative: 0.007 μg/m³ at an air sample of 1.2 m³ (2 h of sampling at an intake rate of 10 L/min) as well as a measuring solution of 20 mL and a dilution factor of 4.

Issue

December 2015 

The complete measuring method is available in the Wiley Online Library: Method for the determination of cadmium and its inorganic compounds in workplace air using ICP mass spectrometry after acid digestion (Air Monitoring Methods, 2017).