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目的建立简便、快速、准确、可靠的面制品中铝的测定方法。方法对铬天青S分光光度法测定铝的反应酸度、铬天青S用量、缓冲剂用量等实验条件进行优化,采用正交试验设计L9(34)优化样品取样量、提取液体积、超声提取时间和温度等实验条件。结果实验优化条件为:样品0.25 g,加入0.5 mol/L氢氧化钠溶液50 m L,于80℃浸提30 min,超声15 min。在溶液p H值为3.5、9.0时,当铬天青加入量>3.0 m L时吸光度均变得稳定。方法的线性范围为10~160μg/L,相关系数为0.999 9,检出限为4μg/L,回收率为89.9%~108.1%。结论本研究简化了样品前处理方法,较好地消除了重金属离子的干扰,确保了测定结果的准确性,适合于基层推广应用。
Objective To establish a simple, rapid, accurate and reliable determination of aluminum in flour products. Methods Chromium Azure S spectrophotometric determination of aluminum reaction acidity, the amount of chrome azure S, the amount of buffer and other experimental conditions to optimize the use of orthogonal design L9 (34) to optimize the sample volume, extract volume, ultrasonic extraction Time and temperature and other experimental conditions. Results The optimal conditions were as follows: 0.25 g sample, 50 mL L-NaOH solution (0.5 mol / L), 30 min extraction at 80 ℃ and 15 min sonication. When the pH value of solution was 3.5 and 9.0, the absorbance became stable when the content of chromazurol was> 3.0 mL. The linear range of the method was 10 ~ 160μg / L, the correlation coefficient was 0.999 9, the detection limit was 4μg / L and the recovery was 89.9% -108.1%. Conclusion This study simplifies the sample pretreatment method, which can eliminate the interference of heavy metal ions and ensure the accuracy of the determination results, which is suitable for the popularization and application of grassroots.