Front. Earth Sci. China 2009, 3(1): 73–79 DOI 10.1007/s11707-009-0017-5 RESEARCH ARTICLE Distribution of phthalate esters in the groundwater of Jianghan plain, Hubei, China Dan ZHANG, Hui LIU (✉), Ying LIANG, Cheng WANG, Hecheng LIANG, Hesheng CAI Key Laboratory of Biogeology and Environmental Geology of Ministry of Education, School of Environmental Studies, China University of Geosciences, Wuhan 430074, China © Higher Education Press and Springer-Verlag 2009 Abstract Samples of groundwater were collected from developmental toxicities in animals (Agarwal et al., 1986). 17 sites in the Jianghan plain in July 2007. Sixteen Recent investigations have shown that several PAEs are phthalate esters (PAEs) were detected in samples collected environmental hormones (Kambia et al., 2001). Since they by using solid-phase extraction (SPE)-gas chromatography are not chemically but physically bound to the polymer (GC). The results show that there were one or several PAEs chains, they may be leached into the environment. The most in all the samples, and the concentrations of total PAEs commonly used PAEs (dimethyl-, diethyl-, di-n-butyl-, ranged from 80.12 to 1882.18 ng/L. Four PAEs, i.e. di-iso- butylbenzyl-, bis (2-ethylhexyl)- and di-n-octyl phthalate butyl phthalate (DIBP), di-n-butyl phthalate (DBP), bis (2- esters) and another plasticizer, the bis(2-ethylhexyl) adipate, ethoxyethyl) phthalate (BEEP) and di (2-ethylhexyl) have been included in the list of priority pollutants in phthalate DEHP) were the dominant species. Among several countries. For example, the US Environmental these, DIBP, DBP and DEHP concentrations were closely Protection Agency (EPA) has established a maximum related to the water supply from the Yangtze River, admissible concentration (MAC) in water of 6 μg/L for bis Hanjiang River and Honghu Lake. However, the distribu- (2-ethylhexyl) phthalate (DEHP) and 0.4 mg/L for bis(2- tion of BEEP was irregular, which may be due to the ethylhexyl) adipate (Fukuwatari et al., 2002; Gomez-Hens application of some kind of products containing BEEP in and Aguilar-Caballos, 2003). the related areas. PAE distribution was irrelevant to the Therefore, PAE contamination has become a hot issue. electrical conductivity and sample depth. Many researchers have paid much attention to the distribution of PAEs in the atmosphere (Wang et al., Keywords phthalate esters (PAEs), groundwater, solid- 2008b), soil (VikelsØe et al., 2002; Li et al., 2006; Cai et phase extraction (SPE), gas chromatography (GC) al., 2008; Zeng et al., 2008a), surface water and sediments (Yuan et al., 2002; Sha et al., 2007; Wang et al., 2008a; Zeng et al., 2008b), landfill (Asakura et al., 2004; Zheng et 1 Introduction al., 2007), and sewage sludges (Cai et al., 2007). However, there are very limited reports about the distribution of Phthalate esters (PAEs) are synthetic compounds which PAEs in groundwater. In many areas in China, ground- have been used as pesticide carriers or insect repellents, as water is used as drinking water. It is meaningful to study well as in cosmetics, fragrances, lubricants and defoaming the distribution and source of PAEs in groundwater so as to agents. However, by far, they are mostly utilized as provide basic knowledge for control. additives in plastic products. Several PAEs are carcino- The Jianghan plain is located in the central and southern genic in animal models (Huber et al., 1996). In addition, area of Hubei Province in the Middle Reach of the Yangtze fl some PAEs and their metabolic products act functionally as River, where oods and water-logging occur frequently. antiandrogens during the prenatal period (Mylchreest et al., This area is low-lying and is characterized by deep alluvial 1998; Moore et al., 2001) and cause reproductive and deposits, many smaller rivers and numerous larger and shallow lakes formed by the meandering of the Yangtze River. The alluvial plain is a honeycomb of waterways Received May 20, 2008; accepted November 4, 2008 bordered by natural levees, and the depressional areas E-mail: [email protected] encompassed by these waterways are dish-shaped in cross 74 Front. Earth Sci. China 2009, 3(1): 73–79 section. The Jianghan plain is one of the important bases of (DPP), diphenyl isophthalate (DPIP) and dibenzyl phtha- Chinese agricultural productivity late (DBZP), were purchased from Dr. Ehrenstorfer GmbH In the present paper, seventeen groundwater samples (Germany); they included an internal standard (benzyl were collected from the eastern part of the Jianghan plain, benzoate), three surrogate standards (500 ng/μLin Hubei, China. Concentrations of 16 PAEs were analyzed acetone) and sixteen PAEs (1000 ng/μL in n-hexane). using solid-phase extraction (SPE)-gas chromatography To avoid contamination, no plastic equipment was used (GC). The distribution of PAEs and the relationship with during sampling and processing. All the glass apparatuses surface water are discussed. were soaked in K2CrO4 sulfuric acid solution at least 12 h, rinsed with organic-free reagent water at least 10 times, and finally baked at 180°C for 4 h. 2 Experiments 2.2 Sampling 2.1 Reagents and chemicals Seventeen groundwater samples were collected in July All solvents, including methylene chloride, hexane, metha- 2007 from the Jianghan plain (Wuhan–Qianjiang section), nol and acetone were of HPLC grade and purchased from Hubei, China. The temperature, electrical conductivity, pH TEDIA (USA) and have a purity of at least 99%. and depth of the samples were recorded during sampling. AccuBOND C18 SPE sorbent was purchased from Agilent. Sampling sites and basic properties are shown in Fig. 1 and Sodium sulfate (granular, anhydrous) was purified by heating Table 1. All samples were sealed in 4 L glass containers at 450°C for 4 h in a SX2-8-13 muffle furnace (Wuhan, and carried back to the laboratory within the day and stored China) and cleaned with methylene chloride before use. at 4°C in a refrigerator before further research. Twenty PAE standard solutions used in this study, including dimethyl phthalate (DMP), diethyl phthalate 2.3 Standards preparation (DEP), diisobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), bis (2-methoxyethyl) phthalate (BMEP), bis(4- A stock standard solution of 100 mg/L of 20 PAEs was methyl-2-pentyl) phthalate (BMPP), diamyl phthalate prepared by diluting the original standard solution with (DAP), bis (2-ethoxyethyl) phthalate (BEEP), hexyl 2- hexane. Calibration standard solutions with concentrations ethylhexyl phthalate (HEHP), dihexyl phthalate (DHP), of 0.5, 1, 5, 10, 20, 30, 40, 50 mg/L were prepared by butyl benzyl phthalate (BBP), bis (2-n-butoxyethyl) diluting the stock standard solution with hexane. Stock and phthalate (BBEP), di (2-ethylhexyl) phthalate (DEHP), calibration standard solutions were stored at 4°C in the dicyclohexyl phthalate (DCP), di-n-octyl phthalate (DOP), refrigerator. The calibration curve was established for each dinonyl phthalate, benzyl benzoate, diphenyl phthalate PAE, and calibration solutions were replaced every month. Table 1 Detailed description of sampling stations station name sampling position pH electrical conductivity/ temperature/°C sampling depth/m – (μS$cm 1) W1 Xiangpu N30°28'07.20";E113°00'06.60" 7.05 580 18.4 30 W2 Xiangpu N30°28'07.20";E113°00'06.60" 7.13 1208 21.4 6 W3 Yuekou N30°30'50.77";E113°05'41.36" 7.61 400 18.6 24 W4 Zoukou N30°19'32.98";E113°54'47.94" 6.83 674 18.8 30 W5 Xinnan N30°06'36.06";E112°56'24.30" 7.07 542 18.8 28 W6 Maoshi N29°55'59.16";E112°54'03.54" 7.05 517 19.6 35 W7 Dongsheng N30°15'13.14";E113°29'17.82" 7.00 930 18.7 5 W8 Hengji N30°11'39.33";E113°09'45.91" 6.93 791 18.8 32 W9 Xichi N30°00'38.26";E113°28'53.07" 7.22 731 19.4 25 W10 Datonghu N30°04'36.24";E113°46'39.48" 6.92 1774 19.8 5 W11 Chenhu N30°30'03.78";E113°32'35.40" 7.13 676 19.4 22 W12 Hanji N30°39'25.44";E113°35'52.20" 7.30 612 19.7 22 W13 Chenghuang N30°37'27.82";E113°46'31.59" 6.80 667 18.7 25 W14 Xinbang N30°25'33.12";E113°44'54.00" 7.02 543 25.0 6 W15 Changhu N30°25'29.11";E114°03'12.78" 7.04 512 18.1 11 W16 Jiangxia N30°17'48.18";E114°01'46.80" 7.38 580 25.3 4 W17 Wuhu N30°10'59.16";E113°45'51.84" 7.13 740 19.4 40 Dan ZHANG et al. Distribution of phthalate esters in the groundwater of Jianghan plain, Hubei, China 75 Fig. 1 Sampling sites in the Jianghan plain 2.4 Sample pretreatment method based on eight-point calibration curve for individual PAEs. Benzyl benzoate was used as the internal For the water phase, samples were extracted using a 12- standard for the quantification of PAEs. port vacuum manifold solid-phase extraction (SPE) system (Supelco, USA). Sample extraction and pretreatment were 2.6 Quality assurance performed according to EPA Method 3535 and 8061a with modification, respectively. Water samples were passed For all the samples, a procedural blank and spiked sample through a 0.45 μm membrane, and 10 μL 100 mg/L surrogate consisting of all reagents was run to check for interference standards (DPP, DPIP, DBZP) were added to 1 L samples. An and cross contamination. Quantifications of PAEs were SPE cartridge (500 mgÂ6 mL) (Agilent, USA) was done with the calibration curves of which the correlation pretreated with 2 mL methylene chloride, 1 mL acetone, coefficients were all higher than 0.99.