Determination of heavy metals in leather and fur by microwave plasma-atomic emission spectrometry

• The application of the MP-AES method in leather and fur was demonstrated.
• MP-AES showed good accuracy and precision by the test of CRM of leather.
• The performance of MP-AES is comparable to that of traditional ICP-AES technology.

A sensitive method for the determination of heavy metals (Cd, Co, Cr, Cu, Hg, Ni and Pb) in leather and fur by microwave plasma-atomic emission spectrometry (MP-AES) based on microwave-assisted acid digestion and a multimode sample introduction system was developed. The leather was subjected to microwave-assisted digestion in a mixed solution of nitric acid and hydrogen peroxide before analysis by MP-AES. Results were compared with those from the standardized method instrument, inductively coupled plasma-atomic emission spectrometry (ICP-AES). Examination of a leather certified reference material (CRM, GSB 16-3087-2013) was used to validate the proposed method by statistical test, with good accuracy and precision shown for all heavy metals analyzed. Under optimum conditions, recoveries of 98.1%–102.6% and relative standard deviations (RSD) of 0.7%–3.0% were achieved, with limits of detection (LOD) ranging from 0.6 mg/kg (Cd) to 5.0 mg/kg (Pb). Furthermore, the MP-AES heavy metals analysis carried out on 23 test leather and fur samples showed an adequate concordance with results obtained from ICP-AES. The benefits of the MP-AES are related to low analysis cost and improved operational safety with nitrogen used for plasma generation. The MP-AES system investigated could offer comparable performance compare to ICP-AES and may be applied as an optional method for routine analysis in leather and fur testing institution.