title: High-throughput determination of seven trace elements in food samples by inductively coupled plasma-mass spectrometry.
abstract: A method was developed for high-throughput determinations of 7 elements in food samples, namely antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and tin (Sn). The samples were digested by closed-vessel microwave-assisted digestion using concentrated nitric acid (HNO3) as the medium, followed by microwave- assisted evaporation to concentrate the sample solutions before dilution to the desired volume. The microwave-assisted evaporation procedure effectively reduced the final acid concentration to around 8% before analysis by inductively coupled plasma-mass spectrometry (ICP-MS). This reduction allows determination by ICP-MS to proceed without further sample dilution, which would affect the detection limit. The method was validated, and method recoveries for As, Cd, Cr, Pb, and Hg were within the certified ranges of the chosen certified reference materials. Recoveries of the 7 elements from spiked samples ranged from 93.1 to 103.6%. The standard uncertainties of precision for the 7 elements were between 3.1 and 4.3%. Interlaboratory comparison studies for As, Cd, and Pb gave z-scores ranging from -0.2 to 0.3.
authors.affiliation: The Government Laboratory of the Hong Kong Special Administrative Region, 7/F, Homantin Government Offices, 88 Chung Hau St, Homantin, Kowloon, Hong Kong.
authors.forename: Kwok Chu
authors.initials: KC
authors.lastname: Chan
authors.forename: Yiu Chung
authors.initials: YC
authors.lastname: Yip
authors.forename: Hei Shing
authors.initials: HS
authors.lastname: Chu
authors.forename: Wing Cheong
authors.initials: WC
authors.lastname: Sham
mesh_terms: D002138:Calibration; D003890:Desiccation; D005504:Food Analysis / Q000191:economics / Q000379:methods*; D006868:Hydrolysis; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D008872:Microwaves; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D014131:Trace Elements / Q000032:analysis*
chemical_list: D007202:Indicators and Reagents; D014131:Trace Elements