论文部分内容阅读
建立了阀切换-非抑制型电导检测离子色谱法测定奶粉中的左旋肉碱的方法。奶粉样品经高纯水溶解后,以乙腈沉淀蛋白,离心,过RP固相萃取小柱和Na柱净化,再通过阀切换的方式进样,经浓缩柱浓缩并冲洗去除基体。以3 mmol/L的甲基磺酸为淋洗液等度洗脱,IonPac CS17阳离子柱交换分离,非抑制电导检测。结果表明:左旋肉碱在17.5~175 mg/kg范围内线性关系良好(r=0.9995);奶粉中左旋肉碱的加标回收率为92.3%~105.2%,相对标准偏差(RSD)在1.4%~4.3%之间;检出限为5 mg/kg。该方法能满足奶粉中左旋肉碱的检测及质量控制要求。
A valve switching - non-suppressed conductivity detection ion chromatography method for the determination of L-carnitine in milk powder was established. After the milk powder sample is dissolved in high-purity water, the protein is precipitated with acetonitrile, centrifuged, purified over an RP solid-phase extraction cartridge and a Na column, and then injected through a valve switch. The concentrated sample is concentrated and washed to remove the matrix. Isocratic elution with 3 mmol / L methanesulfonic acid as eluent, IonPac CS17 cation exchange column separation, non-suppressed conductivity detection. The results showed that L-carnitine had a good linear relationship (r = 0.9995) in the range of 17.5-175 mg / kg, the spiked recoveries of L-carnitine in milk powder ranged from 92.3% to 105.2%, and the relative standard deviations (RSDs) ~ 4.3%; detection limit of 5 mg / kg. The method can meet the L-carnitine in milk powder testing and quality control requirements.