Julshamn Kaare, Maage Amund, Norli Hilde Skaar, Grobecker Karl H, Jorhem Lars, Fecher Peter
National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029 Nordnes, N-5817 Bergen, Norway.
J AOAC Int. 2007 May-Jun;90(3):844-56.
Thirteen laboratories participated in an interlaboratory method performance (collaborative) study on a method for the determination of arsenic, cadmium, mercury, and lead by inductively coupled plasma/mass spectrometry (ICP/MS) after pressure digestion including the microwave heating technique. Prior to the study, the laboratories were able to practice on samples with defined element levels (pretrial test). The method was tested on a total of 7 foodstuffs: carrot puree, fish muscle, mushroom, graham flour, simulated diet, scampi, and mussel powder. The elemental concentrations in mg/kg dry matter (dm) ranged from 0.06-21.4 for As, 0.03-28.3 for Cd, 0.04-0.6 for Hg, and 0.01-2.4 for Pb. The materials used in the study were presented to the participants as blind duplicates, and the participants were asked to perform single determinations on each sample. The repeatability relative standard deviations (RSDr) for As ranged from 3.8 to 24%, for Cd from 2.6 to 6.9%, for Hg from 4.8 to 8.3%, and for Pb from 2.9 to 27%. The reproducibility relative standard deviations (RSDR) for As ranged from 9.0 to 28%, for Cd from 2.8 to 18%, for Hg from 9.9 to 24%, and for Pb from 8.0 to 50%. The HorRat values were less than 1.5 for all test samples, except for the determination of Pb in wheat flour at a level close to the limit of quantitation (0.01 mg/kg dm). The study showed that the ICP/MS method is satisfactory as a standard method for elemental determinations in foodstuffs.
13个实验室参与了一项实验室间方法性能（协作）研究，该研究采用压力消解（包括微波加热技术）后通过电感耦合等离子体质谱法（ICP/MS）测定砷、镉、汞和铅的方法。在研究之前，实验室能够对具有确定元素水平的样品进行练习（预试验）。该方法总共在7种食品上进行了测试：胡萝卜泥、鱼肉、蘑菇、全麦粉、模拟饮食、虾和贻贝粉。以毫克/千克干物质（dm）计的元素浓度范围为：砷0.06 - 21.4、镉0.03 - 28.3、汞0.04 - 0.6、铅0.01 - 2.4。研究中使用的材料以盲样复制品的形式提供给参与者，要求参与者对每个样品进行单次测定。砷的重复性相对标准偏差（RSDr）范围为3.8%至24%，镉为2.6%至6.9%，汞为4.8%至8.3%，铅为2.9%至27%。砷的再现性相对标准偏差（RSDR）范围为9.0%至28%，镉为2.8%至18%，汞为9.9%至24%，铅为8.0%至50%。除了测定小麦粉中接近定量限（0.01毫克/千克dm）的铅外，所有测试样品的HorRat值均小于1.5。该研究表明，ICP/MS方法作为食品中元素测定的标准方法是令人满意的。
