Interlaboratory comparison of instruments used for the determination of elements in acid digestates of solids

Abstract

This paper presents data from an interlaboratory study involving 160 accredited hazardous materials laboratories; the accuracy and precision of four different analytical techniques, inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry, flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry, and hydride generation atomic absorption spectrometry (HGAAS) are compared. Each laboratory performed a mineral acid digestion on five soils spiked with different concentrations of arsenic, cadmium, molybdenum, selenium and thallium. The resulting digestates were analysed on one of the instruments under investigation. The results show that at most concentrations ICP-AES has significantly higher precision and accuracy than the other techniques, but also the highest rates of false positives and negatives. Consistently, HGAAS provided the lowest precision and accuracy.