稀酸浸提水产品中重金属铜、铅和镉

Dilute Acid Extraction of Heavy Metals(Copper, Lead, and Cadmium) in Aquatic Products

以常见的易受重金属污染的水产品(近江牡蛎、翡翠贻贝和基围虾)为对象,研究稀盐酸、稀硫酸和稀硝酸浸提其重金属铜、铅和镉的效果。研究表明,盐酸、硫酸和硝酸的最佳浸提浓度均为2 mol/L,浸提时间分别为10、10、15 min,浸提温度分别为20~90、10~90、10~90℃。与微波消解法相比,3种稀酸浸提水产品中重金属铜、铅和镉的效果为稀硝酸>稀硫酸>稀盐酸。稀盐酸、稀硫酸和稀硝酸浸提的加标回收率分别为69%~97%、97%~116%、98%~111%。综合3种稀酸浸提所需的时长、温度及回收率等因素,稀硫酸和稀硝酸浸提法的操作可行性较高。利用电感耦合等离子体发射光谱仪和酶联免疫法分别检测稀酸浸提液的镉,并对两种检测方法的结果进行线性回归,显示两种检测方法的结果具有显著的线性相关(P<0.01),表明稀酸浸提法可高效快速提取样品中的重金属,满足酶联免疫法检测水产品中重金属的样品前处理要求。

Rapid extraction methods for heavy metals(Cu, Pb, and Cd) with dilute acids(HCl, HNO3, and H2SO4) were investigated and established in the determination of aquatic products(Ostrea rivularis, Perna viridis and Metapenaeus ensi). The results showed that the optimal extraction concentration was 2 mol/L for the three dilute acids. Besides, the optimal extraction time and temperature were 10 min and 20–90 ℃, 10 min and 10–90 ℃, 15 min and 10–90 ℃ for HCl, H2SO4 and HNO3, respectively. Compared with the microwave digestion method, the extraction efficiencies of the heavy metals Cu, Pb, and Cd with these three dilute acids followed the decreasing order: HNO3, H2SO4 and HCl. The spiked recoveries of these heavy metals were 69%–97%, 97%–116% and 98%–111% for dilute solutions of HCl, H2SO4 and HNO3, respectively. Together considering extraction time, temperature and spiked recovery, the extraction methods with H2SO4 and HNO3 solution are feasible. Two groups of Cd concentrations, extracted from aquatic products by dilute acid pretreatment method, were determined by inductively coupled plasma-atomic emission spectrometry(ICP-AES) and ELISA, respectively. Linear regression demonstrated that the results from both analytical techniques were significantly correlated(P < 0.01). This shows that dilute acid pretreatment method could meet the requirements of ELISA assay for heavy metals in aquatic products.