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目的改进国标方法中石墨炉原子吸收光谱法测定食品中铬的检测方法。方法样品经炭化后,于马弗炉中经灰化完全后,冷却,用浓盐酸溶解样灰,用蒸馏水定容至25 ml,盐酸终浓度为3%,用石墨炉原子吸收仪测定。结果对玉米、花生、萝卜、白菜和鸡肉5种样品进行加标测定,回收率为95.0%～105.0%;有证标准物质测定结果相对标准偏差为1.8%～5.4%,且测定值均在证书给定的标准值范围内;该方法最低检出浓度为0.001 mg/kg(当称样量为2 g时)。结论用该方法对食品样品中铬进行测定,其背景干扰小,步骤简单,操作性强,具有良好的准确度和精密度,完全适合于食品样品中铬的测定。
Objective To improve the method for the determination of chromium in food by graphite furnace atomic absorption spectrometry in the national standard method. After the sample was carbonized, it was completely melted in a muffle furnace. After cooling, the asparagus was dissolved in concentrated hydrochloric acid. The volume of the sample was 25 ml with distilled water and the final concentration of hydrochloric acid was 3%. Graphite furnace atomic absorption spectrometry was used. Results Five samples of corn, peanut, radish, cabbage and chicken were spiked with the recoveries of 95.0% -105.0%. The relative standard deviations (RSDs) of the certified reference materials were 1.8% -5.4% Given the standard value range; The minimum detectable concentration of this method is 0.001 mg / kg (when the sample size is 2 g). Conclusion The method for the determination of chromium in food samples, the background interference is small, simple steps, strong operability, with good accuracy and precision, fully suitable for the determination of chromium in food samples.