石墨消解-电感耦合等离子体质谱法测定食品中16种稀土元素

Determination of 16 rare earth elements in food by graphite digestion inductively coupled plasma mass spectrometry

采用石墨消解法作为前处理技术,在对其进行优化的基础上,结合电感耦合等离子体质谱仪建立同时测定食品中16种稀土元素的方法,并与国家标准中的微波消解前处理方法进行比较。通过优化采用铑作为钪、钇的内标物,铼作为铕、钆、铽、镝、钬、铒、铥、镱、镥的内标物,铟作为镧、铈、镨、钕、钐的内标物,用硝酸在125℃时对样品进行消解。结果表明:16种元素在质量浓度0~20μg/L范围内,线性关系良好,相关系数均大于0.999,16种稀土元素的检出限为0.03~0.6μg/kg,定量限为0.06~1.2μg/kg,回收率为80.0%~107.0%,相对标准偏差为0.28%~7.98%。与微波消解法相比,石墨消解法方法快速安全,简单准确。

Using graphite digestion method as a pretreatment technique, based on its optimization, a method for simultaneously determining 16 rare earth elements in food was established by combining inductively coupled plasma mass spectrometry, and compared with the microwave digestion pretreatment method in the national standard. By optimizing the use of rhodium as the internal standard for scandium and yttrium, rhenium as the internal standard for europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium, and indium as the internal standard for lanthanum, cerium, praseodymium, neodymium, and samarium, the samples were digested with nitric acid at 125 ℃. The results showed that the 16 elements had good linear relationships within the mass concentration range of 0-20 μg/L, with correlation coefficients greater than 0.999. The detection limit of the 16 rare earth elements was 0.03-0.6 μg/kg, the quantification limit was 0.06-1.2 μg/kg, the recovery rate was 80.0 %-107.0 %, and the relative standard deviation was 0.28 %-7.98 %. Compared with microwave digestion, graphite digestion method was fast, safe, simple and accurate.