Method for determining N-dimethyl nitrosamine in water, kit and application

Abstract

The invention discloses a method for determining N-dimethyl nitrosamine in water, which is based on a dispersive solid-phase extraction principle, and comprises the following steps: mixing coconut shell activated carbon powder with a water sample, carrying out ultrasonic-assisted dispersion to complete extraction, and carrying out negative-pressure quick suction filtration and elution and then, adding acidic ionic liquid during rotary evaporation, so that volatilization and loss of N-dimethyl nitrosamine in the rotary evaporation process can be reduced. Compared with a traditional solid-phaseextraction method, the time required for analysis is greatly shortened on the premise that the detection sensitivity and the result reliability are guaranteed. Meanwhile, the invention also provides acorresponding on-site sampling kit which is matched with a suction filter and a small ultrasonic instrument to realize on-site sampling, treatment and storage of the water sample, and subsequently, the pretreatment sample solution only needs to be brought back to a laboratory to be concentrated for detection.

Description

technical field [0001] The invention relates to an analysis and detection method, in particular to a liquid chromatography-tandem mass spectrometry detection method, in particular to a method, kit and application for determining N-dimethylnitrosamine in water. Background technique [0002] N-Nitrosodimethylamine (N-Nitrosodimethylamine, NDMA) is a strong polar (log K ow =-0.57) compound, easily soluble in polar solvents such as water, alcohols and dichloromethane. NDMA in drinking water mainly comes from chlorination (free chlorine or chloramine) disinfection. NDMA has extremely strong genotoxicity, and the induced tumors are mainly in the esophagus and liver, and can also produce tumors in the bladder, brain and lungs. The carcinogenicity of the International Cancer Research Center is classified as 2A level, because of its carcinogenic risk (95.71×10 -6 ) is significantly larger than trihalomethane (5.32×10 -6 ) and haloacetic acid (67.55×10 -6 ). At present, my count...

AI Technical Summary

Problems solved by technology

Liquid-liquid extraction mainly uses dichloromethane for extraction. Due to the strong polarity of NDMA and the high distribution ratio in water, the extraction efficiency of this method is low and the amount of organic reagents is large, which limits its promotion and application.

On the other hand, solid-phase extraction is currently the most commonly used method for enriching trace NDMA in water samples. Commonly used solid-phase adsorption materials include coconut shell activated carbon, neutral activated carbon, etc. The method has good stability and high enrichment factor, but for large Volumetric water samples take a long time and the adsorption efficiency is low

Solid-phase microextraction technology is easy to operate and does not require extraction solvents, but at the same time, it is limited by factors such as the type of extraction head material and the nature of the target object, resulting in poor stability of the results and limited scope of application.

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