• Method adopted/last revised: 2008
• Method reapproved: None
• REF/ISBN: IP561-2936450
• Status: Current
• First printed in STM books: January 2008

Scope

This Standard specifies a procedure for the determination of silicon, nickel, chromium, iron and copper content of used lubricating greases by inductively coupled plasma atomic emission spectrophotometry (ICP-AES). The concentration ranges that this method covers are shown below:

Element      Range mg/kg

Silicon          14 to 240
Nickel            3 to 180
Chromium     1 to 160
Iron               7 to 2880
Copper          2 to 132

NOTE 1 - This standard is designed for trend analysis of the elements listed. The precision shown for each element obtained from a round robin study is supplied to provide indicative performance on repeatability and reproducibility. Due to the inhomogeneous nature of the samples a high variance can be expected thus individual measurements should not be used in isolation but as a measure of trend.

NOTE 2 - Results obtained from XRF determinations of the same round robin samples indicated that ICP-AES measurements produced lower results for all elements except Fe where the results were comparable.