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样品经高温水解后,使氯由基体中释放出来,被吸收在去离子水中,然而用Ag/AgCl涂丝电极对、用浓差法测定<0.35ppm的氯,以1ppm标准氯液为参考液,作0—400ppb浓差曲线。对100ppb的氯,变动系数为3.8％;测定时用3微克的标准氯加入,回收测得为3.2微克。涂丝电极的制备,是把表面清洁的银丝,浸于0.01NHCl,以铂丝为阴极,通过0.1mA/cm~2的电流,放置24小时,即得表面光滑的AgCl层。该法与格氏法比较,它快速而简便、且测定下限较低;与pHg_2Cl_2比较,灵敏度虽不及它,但响应时间快五倍,且能用于以V_2O_5为促进剂的高温水介体系,而pHg_2Cl_2在该体系中,由于电位跳跃不停,不能采用。
After the sample was hydrolyzed at high temperature, the chlorine was released from the matrix and absorbed in deionized water. However, Ag / AgCl was used to coat the electrode pairs. Concentrations of <0.35 ppm of chlorine were determined by the concentration difference method, and 1 ppm of standard chlorine solution , For 0-400ppb concentration curve. For 100 ppb of chlorine, the coefficient of variation is 3.8%; when 3 μg of standard chlorine is added for the measurement, 3.2 μg is recovered. The preparation of the coated wire electrode is to clean the surface of the silver wire, immersed in 0.01NHCl, platinum wire cathode, through 0.1mA / cm ~ 2 current, for 24 hours to obtain a smooth surface AgCl layer. Compared with Grignard’s method, the method is quick and simple, and the lower limit of determination is lower. Compared with pHg_2Cl_2, the sensitivity is less than that of Grignard’s method, but the response time is five times faster and can be used for high temperature water-mediated system with V_2O_5 as accelerator, The pHg_2Cl_2 in the system, due to non-stop potential jump, can not be used.