【摘要】 目的:建立用高效液相色谱法测定乳粉中硝酸盐和亚硝酸盐含量的方法。方法:乳粉样品经温水浴,超声萃取,以3%乙酸溶液和0.1 mol/L KOH溶液去脂肪和沉淀蛋白后,进行高效液相色谱测定,色谱柱为Shim pack VP-ODS柱,(5μm,150 mm×4.6 mm),流动相为甲醇-混合磷酸盐溶液(1.25 mmol/L Na2HPO4和1.25 mmol/L KH2PO4及内含4 mmol/L四丁基溴化铵)(体积比为15:85),流速1.0 ml/min,检测波长为220 nm。结果:亚硝酸盐、硝酸盐完全分离,分离度R>1.5,亚硝酸盐和硝酸盐线性范围分别为0.10~10.0μg/ml、0.20~20.0μg/ml,最低检出浓度分别为0.5、1.0 mg/kg,回收率在88.3%~101.3%之间,相对标准偏差<5%(n=6)。结论:该方法简单、快速、灵敏度高,适用于乳粉中硝酸盐和亚硝酸盐含量的同时测定。更多还原

【Abstract】 Objective:To establish an analysis method for nitrite and nitrate in milk powder based on the method of high performance liquid chromatographic(HPLC).Methods:Sample of milk powder was extracted with ultrasonic in warm water,removed protein and fat using acetic acid solution (3%) and potassium hydroxide solution(0.1 mol/L),and then analyzed by HPLC.The HPLC analysis conditions were: chromatographic column Shim pack VP-ODS(5 μm,150 mm×4.6 mm),the ratio of mobile phase methanol-phosphate buffer(1.25 mmol/L disodium hydrogen phosphate,1.25 mmol/L potassium dihydrogen phosphate) that contains 4 mmol/L tetrabutyl-lammonium bromide(V/V) was 15/85,flowing rate 1.0 ml/min,detecting wavelength 220 nm.Results:The resolution factor of nitrite and nitrate was more than 1.5,the linear range of nitrite and nitrate were respectively 0.10～10.0 μg/ml and 0.20～20.0 μg/ml.The detection limits for nitrite and nitrate were respectively 0.5 mg/kg and 1.0 mg/kg.The recovery rate were between 88.3% and 101.3%.the relative standard deviation was less than 5%(n=6).Conclusion:The method is convenient,quick and sensitive and can be used to simultaneously detect the contents of nitrite and nitrate in milk powder.更多还原