Hight S C
US Food and Drug Administration, Center for Food Safety and Applied Nutrition, Elemental Research Branch, Washington, DC 20204, USA.
J AOAC Int. 2000 Sep-Oct;83(5):1174-88.
A modification of the official flame atomic absorption spectrometric (FAAS) method for determining lead and cadmium extracted from ceramic foodware was collaboratively studied. In the modified method, graphite furnace atomic absorption spectrometry (GFAAS) is substituted for FAAS. The modified method also includes mandatory quality control procedures to improve method performance. The extraction procedure of the official method (leaching with 4% acetic acid for 24 h at room temperature) remains unchanged. Seven laboratories analyzed blind duplicate portions of 3 ceramicware leach solutions containing Pb at concentrations of 0.0196, 0.403, and 3.73 microg/mL and Cd at concentrations of 0.00236, 0.0456, and 0.544 microg/mL. Performance of the modified method compared well with that of the official method. The repeatability relative standard deviation (RSDr) ranged from 0.87 to 6.7% for Pb and from 3.7 to 11% for Cd. The reproducibility relative standard deviation (RSDR) ranged from 4.5 to 12% for Pb and from 7.0 to 11% for Cd. Accuracy of collaborator results was 97-98% for Pb and 93-101% for Cd. Quality control results and quantitation limits were excellent. Method quantitation limits varied among laboratories from 0.005 to 0.019 microg/mL for Pb and from 0.0004 to 0.0019 microg/mL for Cd. The modified method was adopted First Action by AOAC INTERNATIONAL.
对官方火焰原子吸收光谱法（FAAS）进行了改进，用于协同研究测定陶瓷餐具中铅和镉的提取量。在改进方法中，用石墨炉原子吸收光谱法（GFAAS）替代了FAAS。改进方法还包括强制性质量控制程序，以提高方法性能。官方方法的提取程序（在室温下用4%乙酸浸提24小时）保持不变。七个实验室分析了3种陶瓷浸出液的盲样重复部分，其中铅的浓度分别为0.0196、0.403和3.73μg/mL，镉的浓度分别为0.00236、0.0456和0.544μg/mL。改进方法的性能与官方方法相当。铅的重复性相对标准偏差（RSDr）范围为0.87%至6.7%，镉为3.7%至11%。铅的再现性相对标准偏差（RSDR）范围为4.5%至12%，镉为7.0%至11%。合作实验室结果的铅准确度为97 - 98%，镉为93 - 101%。质量控制结果和定量限良好。方法定量限在各实验室之间有所不同，铅为0.005至0.019μg/mL，镉为0.0004至0.0019μg/mL。改进方法被美国官方分析化学师协会（AOAC INTERNATIONAL）首次采用。
