中药材圆果中重金属检测的消解方法研究

Determination of Heavy Metal Contents in Chinese Medicinal Materials by Different Pretreatment Methods

探索采用湿法电热板、微波和干法消解法同时消解中药材圆果,用冷原子吸收光谱法测定汞的含量、石墨炉原子吸收光谱法测定砷的含量、火焰原子吸收光谱法分别测定铜、镉、铅、铬、锌的含量。对3种方法的消解效果进行对比。结果表明:在精确度试验中,回收率大于90%的测定方法有:湿法中王水+高氯酸消解汞、砷、铅和镉的含量;湿法中硝酸+高氯酸消解铬、铜、铅和镉的含量;王水+高氯酸和硝酸+高氯酸及微波消解锌的含量。在精密度试验中,王水+高氯酸、硝酸+高氯酸和干法消解汞和砷的过程中,变异系数大于30%,王水+高氯酸、硝酸+高氯酸、干法和微波消解铜、铅、镉、铬、锌的含量时,变异系数都小于10%,平均变异系数达3.3%。综合考虑上述因素,在进行中药材样品重金属分析测试时,根据回收率和操作条件,应采用较高的王水+高氯酸消解汞、砷、铅、镉、铬、锌含量的前处理。

Traditional Chinese medicinal materials were digested by wet hot plate, microwave or dry digestion ways respectively. Mercury was determined by cold atomic absorption spectrometry. Arsenic was determined by GF-AAS. Copper, zinc, chromium, lead and cadmium were determined by Flame Atomic Absorption Spectrometry. The results showed that in the accuracy experiments, the ways which recovery rate over 90% were mercury, arsenic, lead and cadmium digested by aqua regia-perehloric acid, chromium, copper, lead and cadmium digested by nitric acid-perehloric acid system; Zinc di- gested by aqua regia-perehloric acid, nitric acid-perehloric acid system and microwave digestion. In the accuracy experiments, Mercury and arsenic were digested by aqua regia-perehloric acid, nitric acid-perehloric acid system and dry digestion; the relative standard deviations were more than 30%. Chromium, copper, lead, cadmium and zinc were determined by aqua regia-perehloric acid, nitric acid-perehloric acid system, dry digestion and microwave digestion, the relative standard deviations were less than 10%. The average relative standard deviation was 3.3%. The aqua regia-perehloric acid should be adopted in dispelling copper, chromium, lead, cadmium, zinc, mercury, arsenic by recovery rate and operating condition.