Determination Of12Isomers Of Nonylphenol In Reclaimed Water By Gas Chromatography-mass Spectrometry

Nonylphenol （NP） is a kind of typical environmental endocrine disruptors, hasstrong activity of estrogen. NP is a mixture of isomers.Some studies have shown thatestrogen effect of each isomer is different, their damage to environment is alsodifferent, so it is necessary to achieve separation of NPmixture and quantitation ofeach isomer. But the isomers’ physical and chemical properties are similar, theseparation of the isomers is difficμg/Lt. In gneral,NP quantitation ismostly in total.The purpose of this study is to develop a method to achieve quantitation analysis ofNP isomers,and then optimize the extraction method of NP. After the whole methodwas estiblished, we detected the reclaimed water and groundwater from differentdepthes of the area irrigated by reclaimed water.The main contentsare as follows:1.GC-MS（60m*0.25mm*0.25um） was used to separate NP isomers,and12kinds of isomers were isolated from NP mixture;GC-FID and area normalizationmethod were used to determine each isomer’s percentage.The precision of the methodwas good.The method recovery of the12NP isomers was69.4%~129.0%withrelative standard deviation（RSD）0.6%~14.0%.The method detection limit was（9.01~41.4ng/L）.2.Theliquid-liquid extraction of NP pretreatment method was optimized.Resμg/Lts showed that,when60mL methylene chloride was used as extracting agent,60g NaCl was added to salt out, and the water pH was adjusted to pH<1, therecoveries of12NP isomers were highest, which also can meet the test requirements.3.The whole method was applied to the field sample testing. South-easternsuburbs reclaimed water irrigation area in Beijing was studied as an example,and wedetected the reclaimed water and groundwater which collected from different depthesof the area irrigated by reclaimed water. Resμg/Lts showed that:total NP in surfacewater which comed from XiaoHongMen wastewatertreatment plant was357.6~1260.9ng/L; and the content in80m groundwater was ND~1047.9ng/L; Thepollution degree in80m groundwater was: irrigation area in central>west> east. The detection rate of each isomer in the surface water was high;The most high detectionrate in80m groundwater was NP11, NP12.4.The total NP change trend in vertical of two monitoring stations（YangGezhuang Wetland and Feng He）were different. YangGezhuang Wetlandmonitoring stations:total NP was diminishing with the depthes increasing,which wasmainly caused by clay adsorption of NP. Feng He monitoring stations:with theincrease of depth, the change trend of NP was not obvious.Rainfall infiltration,adsorption by soil minerals,microbial activities and others woμg/Ld affect the verticalmigration of NP.