利用流动注射型乙酰胆碱酯酶传感器监测海水中马拉硫磷  

Detection of Malathion in Seawater Using a Flow Injection Type Biosensor Based on the Immobilized Acetylcholinesterase

作　　者：孟范平[1] 何东海[1] 朱小山[1] 杨正先[1] 马冬冬[1] 

机构地区：[1]中国海洋大学环境科学与工程学院,青岛266003

出　　处：《分析化学》2005年第7期922-926,共5页Chinese Journal of Analytical Chemistry

基　　金：国家"十五"863计划项目资助项目(No.2001AA635130)

摘　　要：将乙酰胆碱酯酶(AChE)传感器引入流动注射系统中,研究了传感器连续监测海水中马拉硫磷的可行性。系统中的载液为不含马拉硫磷的海水。传感器适宜的工作条件为:载液和样品的流速为0.39mL/min,进样时间为20min;底物(碘化硫代乙酰胆碱)溶液的浓度为41.6mmol/L,注射量为40μL。利用次氯酸钠溶液对含马拉硫磷的海水样品进行预氧化处理,可以大大提高传感器的灵敏度,对马拉硫磷的检出限达到0.05μg/L;而不进行氧化时的检出限为1.3μg/L。另外,海水样品经过预氧化处理后,传感器对其中0.1～10μg/L的马拉硫磷具有良好的线性响应关系(r=0.991)。测定含马拉硫磷的海水样品后,向传感器持续通入0.5mmol/L的2PAM溶液15min,可以完全恢复受到100μg/L马拉硫磷抑制的固定化酶活性。结果表明:所设计的酶传感器适于海水中马拉硫磷的连续、灵敏和准确监测。With the help of a flow injection analysis (FIA) system, the possibility to determine malathion in seawater continuously by the biosensor based on the immobilized acetylcholinesterase (ACH) was studied. In this system, the carrier was seawater without malathion. The feasible work conditions for the biosensor were as follows: the flow rate was 0.39 mL/min for both the carrier and samples; the inhibition time from the samples lasted for 20 minutes; the concentration and injection volume of the substrate, acetylthiocholine iodide, were 41.6 mmol/L and 40 mu L, respectively. The sensitivity of the biosensor had a remarkable rise when the samples were oxidized previously by hypochlorous sodium. The detection limits of the biosensor for malathion in seawater were 1.3 mu g/L and 0.05 mu g/L before and after pre-oxidation respectively. In addition, for the samples with malathion from 0.1 mu g/L to 10 mu g/L, a good linearity (r = 0.991) between the response of biosensor and the concentration of malathion could be obtained. After a sample containing malathion less than 100 mu g/L was measured, the inhibited activity of immobilized AChE could be reactivated completely by transporting pyridine-2-aldoxime of 0.5 mmol/L into the biosensor for 15 minutes. These showed that the biosensor was suitable for the sensitive, accurate and continuous detection of organophosphorus pesticides in seawater.

关 键 词：马拉硫磷 酶传感器 海水 流动注射 预氧化处理 乙酰胆碱酯酶 次氯酸钠溶液 水样品 注射系统 连续监测 进样时间 响应关系 固定化酶 检出限 min 注射量 灵敏度 载液 硫代 碘化 

分 类 号：O661.1[理学—分析化学] O657.1[理学—化学]