饮用水中微量碘化物的测定对于防治地方性甲状腺肿有着重要意义。目前常用的碘量比色法,接触法等化学方法都有一定的局限性和不足之处。前者灵敏度低,后者所用试剂多,操作条件较苛刻。有人(Joerin MM:A rapid method of determining tot...
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饮用水中微量碘化物的测定对于防治地方性甲状腺肿有着重要意义。目前常用的碘量比色法,接触法等化学方法都有一定的局限性和不足之处。前者灵敏度低,后者所用试剂多,操作条件较苛刻。有人(Joerin MM:A rapid method of determining total iodine in bovine *** 100:7,1975)曾用四甲基四胺基二苯甲烷作为显色剂来测定牛奶中的碘。我们根据其原理提出了水中微量碘化物快速测定法。经实验测定具有灵敏度高、操作简便、节省试剂、分析速度快等特点。
A new, rapid methodology for trace analysis using solid-phase extraction is described. The two-step methodology is based on the concentration of an analyte onto a membrane disk and on the determination by diffuse refl...
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A new, rapid methodology for trace analysis using solid-phase extraction is described. The two-step methodology is based on the concentration of an analyte onto a membrane disk and on the determination by diffuse reflectance spectroscopy of the amount of analyte extracted on the disk surface. This method, which is adaptable to a wide range of analytes, has been used for monitoring ppm levels of iodine and iodide in spacecraft water. Iodine is used as a biocide in spacecraft water. For these determinations, a water sample is passed through a membrane disk by means of a 10-mL syringe that is attached to a disk holder assembly. The disk, which is a polystyrene- divinylbenzene composite, is impregnated with poly(vinylpyrrolidone) (PVP), which exhaustively concentrates iodine as a yellow iodine-PVP complex. The amount of concentrated iodine is then determined in only 2 s by using a hand-held diffuse reflectance spectrometer by comparing the result with a calibration curve based on the Kubelka-Munk function. The same general procedure can be used to determine iodide levels after its facile and exhaustive oxidation to iodine by peroxymonosulfate (i.e., Oxone reagent). For samples containing both analytes, a two-step procedure can be used in which the iodide concentration is calculated from the difference in iodine levels before and after treatment of the sample with peroxymonosulfate. With this methodology, iodine and iodide levels in the 0.1-5.0 ppm range can be determined with a total workup time of similar to60 s with a RSD of similar to6%.
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