High-sensitivity testing method capable of simultaneously implementing measurement of multiple negative ions

Abstract

The invention relates to a high-sensitivity testing method capable of simultaneously implementing measurement of multiple negative ions. The analysis objects not only comprise Cl<->, NO2<->, NO3<-> and SO4<2->, but also comprise easily polarized ions Br<->, I<-> and S2O3<2->. A negative ion analysis column AS9-HC and a protection column AG9-HC are adopted together, the washing solution comprises Na2CO3 and NaHCO3 in a concentration ratio of 9mm: 1mm, the flow rate of the washing solution is 0.9 to 1.1ml / min, the detector is an electrical conductivity detector, the current of a suppressor is 88mA, the temperature of the columns and the temperature of a detection cell are 28 to 32 DEG C, and the used quantitative ring is a polyether-ether-ketone (PEEK) tube with inside diameter of 0.030in, outside diameter of 1 / 16in and length of 7m. The lower detection limits of the ions are low and reach nano scale, namely the lower detection limit of Cl<-> is 0.61 nanometer, the lower detection limit of the NO2<-> is 0.94 nanometer, the lower detection limit of the NO3<-> is 0.93 nanometer, the lower detection limit of the SO4<2-> is 0.81 nanometer, the lower detection limit of the Br<-> is 0.90 nanometer, the lower detection limit of the I<-> is 2.48 nanometers and the lower detection limit of the S2O3<2-> is 1.84 nanometers. The method is simple and convenient for operation, and can be used for implementing high-sensitivity measurement of multiple negative ions indoors or outdoors.

Description

technical field [0001] The invention belongs to the technical field of ion chromatography analysis, and in particular relates to a high-sensitivity test method capable of simultaneously realizing the determination of multiple anions in water. It can be used indoor or in the field to treat various anions (Cl - , NO 2 - , NO 3 - , SO 4 2- 、Br - , I - , S 2 o 3 2- ) analysis. Background technique [0002] In nature, hot spring water, seawater, groundwater, industrial wastewater and other water bodies contain different types and concentrations of anions, including the more stable Cl - , NO 2 - , NO 3 - , SO 4 2- and Br, which is easily polarized and prone to redox reactions - , I - , S 2 o 3 2- , the classic wet chemical analysis can only be determined separately by different chemical methods, and has the disadvantages of much interference, long time, and low sensitivity. [0003] Ion chromatography is suitable for the simultaneous analysis of multiple an...

AI Technical Summary

Problems solved by technology

Conductometric detectors are versatile, but have low sensitivity and high detection limits, especially for easily polarizable anions such as Br - , I - , S 2 o 3 2- etc.), because these ions are prone to redox reactions, the detection sensitivity is low and there are many interferences

The amperometric detector is based on the current change when the target ion undergoes a redox reaction on the electrode surface, and has a high sensitivity. - , NO 3 - , SO 4 2- Plasma

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