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目的建立油条中铝含量的电感耦合等离子体质谱检测方法(ICP-MS)。方法用5 ml硝酸和2 ml过氧化氢为消解溶剂对样品进行微波消解,消解液蒸缩至1 ml左右,用纯水定容至50 ml,电感耦合等离子体质谱法进行定量检测。方法考察了酸度对响应值的影响,用1.0 ng/ml混合调谐液优化仪器工作条件,选用钪作为内标元素校正基体干扰和漂移。结果铝的质量浓度为0 mg/L~5.0 mg/L时,线性关系良好,线性回归方程为y=5 530x+62 184,相关系数(r)为0.999 3。方法的检出限为0.1μg/L。添加3种浓度水平的铝标准溶液测定方法的回收率,平均回收率为92.0%~102.0%,相对标准偏差为0.7%~3.2%。并应用该方法对油条样品中铝的含量进行了测定,发现15份样品中铝含量全部超标,含量为375 mg/kg~926 mg/kg。结论该方法灵敏度高、准确度好、检出限低、线性范围宽,适用于油条等面制食品中铝的测定。
Aim To establish an ICP-MS method for the determination of aluminum content in the fillet by inductively coupled plasma mass spectrometry (ICP-MS). Methods The samples were digested with 5 ml of nitric acid and 2 ml of hydrogen peroxide as digestion solvent. The digestion solution was concentrated to about 1 ml. The volume of the digestion solution was reduced to 50 ml with inductively coupled plasma mass spectrometry. Methods The effect of acidity on the response was investigated. The working conditions of the instrument were optimized with 1.0 ng / ml mixed liquid, and scandium was selected as the internal standard to correct the interference and drift of substrate. Results The linearity was good when the mass concentration of aluminum was 0 mg / L ~ 5.0 mg / L. The linear regression equation was y = 5 530x + 62 184 and the correlation coefficient (r) was 0.999 3. The detection limit of the method was 0.1 μg / L. The recoveries of the three standard solutions of aluminum standard solution with the average recoveries of 92.0% ~ 102.0% and the relative standard deviations of 0.7% ~ 3.2% were obtained. The method was used to determine the content of aluminum in the sample. The content of aluminum in the 15 samples exceeded the standard, and the content was 375 mg / kg ~ 926 mg / kg. Conclusion The method has high sensitivity, good accuracy, low detection limit and wide linear range. It is suitable for the determination of aluminum in instant noodles.