Research And Practice In Inspection Methods Of Nitrosamines And Precursors In Drinking Water Of Tai Lake In Suzhou

N-DBPs are a kind of by-products with strong carcinogenicity,mutagenicity,deformity found in drinking water.Of all N-DBPs,NDMA has the highest detection frequency and high concentration in drinking water.The USEPA and the UNEP have made it a priority pollutant for its high toxic in a very low concentration(0.7 ng/L).Of all precusors turning into NDMA,DMA is the directest precursor.China has not yet set standards of N-DBPs in drinking water,but due to lack of research on them,this study aims to establish a series of methods suitable for detecting the concentration of N-DBPs and precursors in drinking water of Tai Lake in suzhou,taking NDMA and its precursor DMA as the representative substances,to provide references for the development of the detection method of N-DBPs in drinking water.In this study,SPME-GC/MS and SPE-HPLC were selected to detect the concentration of NDMA in drinking water.HS-GC/MS and Derivation-GC/MS were used to detect the concentration of DMA in drinking water.In the study of detecting the concentration of NDMA with SPME-GC/MS and SPE-HPLC,SPME-GC/MS set pH to 7,NaCl addition to 0.4 g/mL,extraction temperature to 60?,the extraction time to 30 min,GC column to HP-5 and selected characteristic ions m/z for 42;SPE-HPLC extracted NDMA with coconut shell activad carbon extracting column,set mobile phase to methanol/water(5/95),flowing rate to 1.0 mL/min by a VenusilMp-C18 chromatographic column,temperature of column to 30?,detection wavelength to 228 nm and sample size to 100 ?L.The Result of study showed that the correlation coefficients of SPME-GC/MS and SPE-HPLC what have good linear relationship in the interval of 20 ng/L~200 ng/L and 1.0 ?g/L~50.0 ?g/L to 100.0?g/L~200.0 ?g/L,respectively,were 0.9996 and 0.9982/0.9998,the RSDs were2.05%~2.34% and 2.05%~4.75%,the LOQs were 20 ng/L and 1.0 ?g/L,the LODs were0.7 ng/L and 1.1 ng/L and the recovery were 95.4%~102.0% and 89.6%~100.01%,respectively.The concentration of NDMA in the actual water did not exceed the international standard,and the concentration in winter is more than that in summer.The RSDs of NDMA were 3.93% and 6.99% in raw water,undetected in product water and6.85% and 10.84% in pipe water,respectively.The recovery of NDMA in actual water were95.4%~102.0% and 89.6%~100.01%,respectively.In the study of detecting the concentration of DMA in drinking water with HS-GC/MS and Derivation-GC/MS,HS-GC/MS set extraction temperature at 80?, temperature of quantitative ring at 90?,temperature of transmission-line at 150?,extraction time to 30 min,injected samples with HP-5 GC column and selected characteristic ions m/z for 44.1 and 45.1;Derivation-GC/MS determined the concentration of DMA in drinking water by experimental conditions of HS-GC/MS with the characteristic ions m/z for 77.1,141.0 and 185.0 after deriving DMA to benzenesulfonamide with benzene sulfonamide.The Result of study showed that the correlation coefficients of HS-GC/MS and Derivation-GC/MS what have good linear relationship in the interval of 0.5?g/L~200?g/L and 100.0 pg/L~1000.0 pg/L to 1.0ng/L~100.0 ng/L,respectively,were 0.9987 and 0.9998/0.9997,the RSDs were1.38%~6.22%,the LOQs were 0.5?g/L and 0.1 ng/L,and the LODs were 0.2 ng/L and0.01ng/L,respectively.The concentration of DMA in the actual water did not exceed the international standard,and the concentration in winter is more than that in summer.The RSDs of DMA were 10.48%and 0.52%in raw water,undetected in product water and12.67%and 2.27%in pipe water,respectively.The recovery of NDMA in actual water were86.4%~95.3%and 91.8%~100.1%,respectively.Based on the comparison about the linear relationship,RSDs,LOQs,LODs,recovery and other parameters of the detection methods and the actual application,it is found that SPME-GC/MS and Derivation-GC/MS are more suitable for the rapid and accurate detection of the concentration of N-DBPs and precursors in the drinking water of Tai Lake in suzhou.