茶叶中农药残留检测的样品前处理研究进展

样品前处理是建立各种检测方法中耗时最多、最易引起误差的关键环节之一。综述了茶叶中农药残留检测的样品前处理技术,包括索氏提取、震荡提取、超声提取、固相萃取、固相微萃取、微波辅助萃取、搅拌棒吸附萃取、加速溶剂萃取、超临界流体萃取、凝胶渗透色谱和基质固相萃取技术的研究进展。     

气相色谱-质谱法测定水源水中的4种邻苯二甲酸酯

目的:建立气相色谱-质谱测定水中邻苯二甲酸酯的方法.方法:采用固相萃取前处理技术对水样进行提取、富集,以甲醇为洗脱溶剂将组分洗脱,气相色谱-质谱法测定.结果:实验中对色谱条件进行优化,方法的检出限为0.7～6.8μg/L,4种邻苯二甲酸酯测定的相对标准偏差在3.25%～7.18%之间,回收率在79.8%～95.2%之间.结论:本方法能够满足水中痕量邻苯二甲酸酯含量的测定.     

氯酚的分析技术研究进展北大核心CSCD

氯酚是氯取代苯酚类化合物的总称,其中2,4-二氯酚、2,4,6-三氯酚和五氯酚被许多国家列为优先控制的污染物.随着对氯酚监测研究的逐步深入,各种新型的痕量富集净化和检测技术不断涌现。本文主要综述了氯酚的液液萃取、液相微萃取、固相萃取、固相微萃取、搅拌棒吸附萃取、索氏提取、加速溶剂萃取和QuEChERS等样品前处理新技术及气/质联用、液/质联用和毛细管电泳等分析新方法,并对氯酚微量检测的发展趋势进行了展望。     

大气细颗粒物(PM2.5)中16种邻苯二甲酸酯的超声提取-气相色谱-质谱法测定

目的建立大气细颗粒物(PM2.5)中16种邻苯二甲酸酯类化合物的气相色谱质谱检测方法。方法空气样品经玻璃纤维滤膜采集,经丙酮-正己烷(2:8,v/v)超声提取后用气相色谱质谱法测定。结果 16种邻苯二甲酸酯类化合物在0~10.0mg/L范围内线性良好,最低检出限为0.0007~0.0057mg/L,相对标准偏差为0.43%~9.84%,回收率为76.4%~115.7%。结论该方法前处理步骤简单,回收率较高,可用于大气细颗粒物中邻苯二甲酸酯类化合物的测定。     

氯酚的分析技术研究进展

氯酚是氯取代苯酚类化合物的总称,其中2,4-二氯酚、2,4,6-三氯酚和五氯酚被许多国家列为优先控制的污染物.随着对氯酚监测研究的逐步深入,各种新型的痕量富集净化和检测技术不断涌现。本文主要综述了氯酚的液液萃取、液相微萃取、固相萃取、固相微萃取、搅拌棒吸附萃取、索氏提取、加速溶剂萃取和QuEChERS等样品前处理新技术及气/质联用、液/质联用和毛细管电泳等分析新方法,并对氯酚微量检测的发展趋势进行了展望。     

索氏与超声法提取PM_(2.5)中多环芳烃的比较

目的比较索氏提取法与超声提取法对颗粒物中苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、二苯并[a,h]蒽、茚并[1,2,3-c,d]芘、苯并[g,h,i]苝的提取效果。方法对加标的空白滤膜以及采样滤膜用索氏提取法及超声提取法进行处理、用高效液相色谱—荧光检测器测定,计算两种样品前处理方法的相对标准偏差(RSD)及加标回收率并进行比较。结果索氏提取法与超声提取法的相对标准偏差分别为3.6%、2.9%。索氏提取法和超声提取法对空白滤膜的加标回收率分别为91.7%和90.3%,对6种物质回收率的标准差分别为18.5%、2.8%,索氏提取法与超声提取法对采样滤膜的加标回收率分别为89.0%、83.3%,回收率的标准差分别为1.7%、3.1%。在实际样品测定的比较中,两种样品前处理方法取得了相近的结果。结论索氏提取法处理步骤多,影响结果的因素较多;超声提取法操作简便,操作过程对结果的影响较小,结果比较稳定。超声提取法是一种比较实用、快速的样品前处理方法。     

奶粉中二噁英前处理方法的探讨

[目的]建立快速溶剂萃取(ASE)的前处理方法,并改进纯化步骤。采用该前处理方法将国际二噁英标准参考物质进行验证。[方法]采用ASE法和索氏提取2种提取方法对奶粉样品进行充分萃取,再选用FMS专用净化装置对样品进行纯化,采用同位素稀释,以各化合物的同位素标记物为回收率内标,以13C-1,2,3,4-TCDD和13C-1,2,3,7,8,9,-HxCDD为定量内标。用高分辨气相色谱(HRGC)和高分辨双聚焦质谱(HRMS)联用技术进行定性和定量分析。[结果]ASE和索氏提取前处理所得的同位素标记化合物平均回收率分别为66.9%和66.5%,测定实际样品的相对标准偏差分别为18.4%和12.3%。[结论]通过比较ASE与索氏提取2种方法,ASE前处理便捷、时间短、所需溶剂少,回收率和精密度都符合美国EPA1613中的要求,通过用该法测定,结果也接近了欧盟2002/69/EC的规定,即每次测定的同位素标记物回收率不少于60%,如单个化合物的TEQ量小于10%总量TEQ时,不受上述限制。     

固相微萃取技术在挥发性有机化合物分析中的应用进展

挥发性有机化合物（ＶＯＣｓ）是一类重要的环境有机污染物［１］,由于这类污染物种类较多,大多数以较低的浓度存在,其存在样品又具有多样性,因此,必须经过前处理后,才能进行分析。传统的样品处理技术很多,包括液萃取、蒸馏、索氏萃取等,但大多操作繁杂费时,都不...     

小白菜中有机磷残留量测定前处理方法比较

目的 采用三种前处理方法检测小白菜中有机磷,以此对比不同方法间的提取差异. 方法 采用固相支持液-液萃取、QuEChERS、液-液萃取三种不同的前处理方法对小白菜样品进行前处理,用毛细管气相色谱法脉冲火焰光度检测器对处理后样品中的有机磷类农药残留进行测定,并对不同前处理方法的样品测定结果的回收率、阳性样品测定值进行比较. 结果 三种方法的测定值回收率和阳性样品测定结果经x2检验和t检验,测定值回收率、阳性样品测定结果差异无统计学意义. 结论 QuEChERS法较为方便简单、溶剂消耗量少,值得推广.     

人体卵泡中邻苯二甲酸酯代谢物的固相萃取-高效液相色谱测定法

目的 研究固相萃取-高效液相色谱法同时测定人体卵泡中4种邻苯二甲酸酯代谢物的方法。方法 采用固相萃取对卵泡样品进行前处理,固相萃取柱采用HLB小柱,选用3ml乙腈、3 ml乙酸乙酯和3ml乙醚作为洗脱剂对小柱进行洗脱。选择C6H5色谱柱,以乙腈-水体系为流动相,以高效液相色谱方法测定邻苯二甲酸酯代谢物。结果 4种邻苯二...     

室内降尘中邻苯二甲酸酯污染特征分析

目的 了解邻苯二甲酸酯在室内环境中的污染状况.方法 分别选取北京地区10户家庭住宅、10间办公室和10间学生宿舍进行室内降尘取样,采用高效液相色谱法测定降尘中的7种邻苯二甲酸酯类化合物,利用非参数检验进行统计分析.结果 室内降尘中主要存在邻苯二甲酸(2-乙基己基)酯(DEHP)、邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二环己酯(DCHP)污染,其中DEHP的含量范围为28～6073 mg/ks.是检出浓度最高的物质.对不同类型房间进行比较,发现家庭住宅邻苯二甲酸酯污染最严重,办公室次之,学生宿舍污染最小.Kumkal-Wallis H检验分析表明在这3种房间类型中,邻苯二甲酸丁基苄基酯(BBP)、DEHP和DCHP浓度差异有统计学意义(P<0.05).Spearman相关分析表明,DBP与BBP、DBP与DCHP之间均存在正相关关系(P<0.05),但相关关系并不密切(r<0.5).结论 家庭住宅中DEHP污染较为严重,应引起重视.

Abstract：

Objective To investigate the pollution of phthalate ester in indoor environment. Methods Settled dust samples from 10 households, 10 offices and 10 student dormitories in Beijing were collected. Seven kinds of phthalate esters in these samples were determined with solid phase extraction-high performance liquid chromatography (SPE-HPLC) .Dates were analyzed statistically by nonparametric tests. Results The main phthalate esters in dust were di (2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and dicyclohexyl phthalate (DCHP). Of phthalate esters, DEHP with the range of 28-6 073 mg/kg had the highest concentration in indoor dust. The total level of phthalate esters in households was the highest, offices followed, student dormitories was the last. The Kurskal-Wallis H test showed that the concentrations of BBP, DEHP and DCHP in dust were significantly different in 3 types of rooms (P<0.05). Spearman's correlation analysis showed that significantly positive correlations were found between DBP and both BBP and DCHP (r<0.5, P<0.05). Conclusion DEHP pollution in household environment is heavy. It should be taken into account.     

The association between phthalates in dust and allergic diseases among Bulgarian children

BACKGROUND: Recent studies have identified associations between the concentration of phthalates in indoor dust and allergic symptoms in the airways, nose, and skin. OBJECTIVES: Our goal was to investigate the associations between allergic symptoms in children and the concentration of phthalate esters in settled dust collected from children's homes in Sofia and Burgas, Bulgaria. METHODS: Dust samples from the child's bedroom were collected. A total of 102 children (2-7 years of age) had symptoms of wheezing, rhinitis, and/or eczema in preceding 12 months (cases), and 82 were nonsymptomatic (controls). The dust samples were analyzed for their content of dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP). RESULTS: A higher concentration of DEHP was found in homes of case children than in those of controls (1.24 vs. 0.86 mg/g dust). The concentration of DEHP was significantly associated with wheezing in the preceding 12 months (p = 0.035) as reported by parents. We found a dose-response relationship between DEHP concentration and case status and between DEHP concentration and wheezing in the preceding 12 months. CONCLUSIONS: This study shows an association between concentration of DEHP in indoor dust and wheezing among preschool children in Bulgaria.     

Metabolites of the plasticizer di (2-ethylhexyl) phthalate in urine samples of workers in polyvinylchloride processing industries

Summary Little is known about occupational exposure to the plasticizer di(2-ethylhexyl)phthalate (CAS number 117-81-7), a compound widely used in polyvinylchloride (PVC) plastics. We have studied the uptake of DEHP in workers by determining the concentrations of four metabolites of DEHP in urine samples, i.e., mono(2-ethylhexyl)phthalate (MEHP), mono (5-carboxy-2-ethylpentyl)phthalate, mono(2-ethyl-5-oxohexyl)phthalate, and mono(2-ethyl-5-hydroxyhexyl)phthalate. In addition DEHP concentrations in the air were determined by personal air sampling. Nine workers in a PVC boot factory exposed to a maximum of 1.2 mg/m³ DEHP showed an increase in the urinary concentrations of all four metabolites over the workshift. These results were obtained on both the first and the last day of the workweek. With the exception of MEHP, the increases in the concentrations of the metabolites during a workday were statistically significant. Six workers from a PVC cable factory exposed to a maximum of 1.2 mg/m³ DEHP showed a one-to fourfold increase in the concentrations of the four metabolites over the workshift, but these increases were not statistically significant. These results indicate that measurement of DEHP metabolites in urine samples may be of use for monitoring the occupational exposure to DEHP.     

以黄浦江为水源的管网末梢水中微量有机物污染现状

目的研究上海市以黄浦江为水源的管网水中微量有机物污染状况。方法采用固相萃取技术,以1g XAD-2和3g402树脂吸附饮水中有机物,30%丙酮-甲醇洗脱,根据美国EPA推荐的优先控制污染物类别,采用18种GC/MS方法检测。结果检出有机污染物10类142种,主要包括邻苯二甲酸酯类,酚类、胺类、醇酸酯类、脂肪烃类、卤代烷烃类、单/多环芳香族化合物、杂环化合物、醛/酮等化学物。结果表明水中邻苯二甲酸二丁酯、4-枯基苯酚、N-苯基-β-萘胺含量相对较高。其中,邻苯二甲酸二丁酯和邻苯二甲酸二辛酯属EPA推荐的水体优先控制污染物,同时发现饮用水中含除草剂-莠去津和利谷隆和雌激素-3-脱氧雌二醇。结论以黄浦江为水源的饮用水污染谱复杂,所检出有机污染物多数未纳入国家标准。     

Urine phthalate determinations as an index of occupational exposure to phthalic anhydride and di(2-ethylhexyl)phthalate

Although it has been estimated that over 600 000 workers in the United States are exposed to di(2-ethylhexyl)phthalate (DEHP), an animal carcinogen, and that over 100 000 are exposed to phthalic anhydride (PA), few data are available on levels of phthalates in biological fluids of these workers. For a determination of occupational exposure to PA and DEHP at a plant manufacturing DEHP from PA and 2-ethylhexanol, air samples were taken for PA and DEHP, and pre- and postshift urine samples were collected for the determination of total phthalates. Urine samples were obtained from 48 workers in jobs with high exposure to phthalates and from 47 workers in jobs with low exposure. The airborne concentrations of DEHP ranged from 20 to 4 110 micrograms/m3, and the concentrations of PA ranged from 4 to 203 micrograms/m3. The most heavily exposed workers had the highest mean postshift urine phthalate concentration (geometric mean 7.6 nmol/ml) (p = 0.015), and also the greatest mean increase (4.4 nmol/ml) in preshift to postshift urine phthalate levels. Twofold increases over the shift in urine phthalate concentration and postshift phthalate levels of greater than 10 nmol/ml were observed in 8 (25%) of 32 chemical operators, but in none of 52 other workers. These data suggest that measurement of urine phthalate levels may have utility for monitoring the exposure of workers manufacturing or using PA.     

Internal exposure of the general population to DEHP and other phthalates--determination of secondary and primary phthalate monoester metabolites in urine

A number of phthalates and their metabolites are suspected of having teratogenic and endocrine disrupting effects. Especially the developmental and reproductive effects of di(2-ethylhexyl)phthalate (DEHP) are under scrutiny. In this study we determined the concentrations of the secondary, chain oxidized monoester metabolites of DEHP, mono(2-ethyl-5-hydroxyhexyl)phthalate (5OH-MEHP) and mono(2-ethyl-5-oxo-hexyl)phthalate (5oxo-MEHP) in urine samples from the general population. The utilization of the secondary metabolites minimized any risk of contamination by the ubiquitously present phthalate parent compounds. Included in the method were also the simple monoester metabolites of DEHP, dioctylphthalate (DOP), di-n-butylphthalate (DnBuP), butylbenzylphthalate (BBzP) and diethylphthalate (DEP). Automated sample preparation was performed applying a column switching liquid chromatography system enabling online extraction of the urine on a restricted access material (RAM) and separation on a reversed phase analytical column. Detection was performed by negative ESI-tandem mass spectrometry in multiple reaction monitoring mode and quantification by isotope dilution. The excretion of DEHP and the other phthalates was studied by analyzing first morning urine samples from 53 women and 32 men aged 7-64 years (median: 34.2 years) living in northern Bavaria (Germany) who were not occupationally exposed to phthalates. Phthalate metabolites, secondary and primary ones, were detected in all specimens. Concentrations were found to vary strongly from phthalate to phthalate and subject to subject with differences spanning more than three orders of magnitude. Median concentrations for excretion of DEHP metabolites were 46.8 microg/L for 5OH-MEHP (range 0.5-818 microg/L), 36.5 microg/L for 5oxo-MEHP (range 0.5-544 microg/L), and 10.3 microg/L for MEHP (range:<0.5 (limit of quantification, LOQ) to 177 microg/L). A strong correlation was found between the excretion of 5OH-MEHP and 5oxo-MEHP with a correlation coefficient of r=0.991, indicating close metabolic proximity of those two parameters but also the absence of any contaminating interference. Median concentrations for the other monoester metabolites were for mono-n-butylphthalate (MnBuP) 181 microg/L, for monobenzylphthalate (MBzP) 21.0 microg/L, for monoethylphthalate (MEP) 90.2 microg/L and for mono-n-octylphthalate (MOP)<1.0 microg/L (LOQ). These results will help to perform health risk assessments for the phthalate exposure of the general population.     

Occurrence of phthalate esters in the environment of The Netherlands

Overviews of levels of n-dibutylphthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP) found in freshwater, marine water, sediment, and fish in the Netherlands are given. Sampling spanned a 9-month period (all seasons except winter) and allowed assessing whether phthalate levels are season dependent. Results obtained are compared to data reported for other Western European countries and a fugacity-based modeling approach is used to assess whether there is equilibrium among the various compartments. Highest levels of dissolved DBP and DEHP were found in freshwater samples, whereas these compounds were usually below the limit of detection (LOD) in marine water and sediment. Median levels were log-normally distributed; statistical analysis showed that sampling season is not a relevant determinant parameter. Similar results were obtained for the freshwater sediment compartment, with DEHP levels exceeding concentrations of DBP. DBP levels in fish were often below the LOD. Nevertheless, mean values around 1.8 microg kg(-1) wet fish were found for both DEHP and DBP. Fugacity calculations revealed that especially for DEHP there is no equilibrium among the compartments. DEHP emissions are directed to water, whereas the calculations reveal that sediments provide a sink for DEHP and there is net transport to air. Although it has been suggested that water is the primary compartment for DBP, fugacity plots suggest that air is the compartment to which emissions are directed dominantly. The data reported are in line with values found in Western Europe.     

Phthalate metabolites in urine samples from Danish children and correlations with phthalates in dust samples from their homes and daycare centers

Around the world humans use products that contain phthalates, and human exposure to certain of these phthalates has been associated with various adverse health effects. The aim of the present study has been to determine the concentrations of the metabolites of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(iso-butyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) in urine samples from 441 Danish children (3–6 years old). These children were subjects in the Danish Indoor Environment and Children's Health study. As part of each child's medical examination, a sample from his or her first morning urination was collected. These samples were subsequently analyzed for metabolites of the targeted phthalates. The measured concentrations of each metabolite were approximately log-normally distributed, and the metabolite concentrations significantly correlated with one another. Additionally, the mass fractions of DEP, DnBP, DiBP and BBzP in dust collected from the children's bedrooms and daycare centers significantly correlated with the concentrations of these phthalates’ metabolites (monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP) and monobenzyl phthalate (MBzP), respectively) in the children's urine. Such correlations indicate that indoor exposures meaningfully contributed to the Danish children's intake of DEP, DnBP, DiBP and BBzP. This was not the case for DEHP. The urine concentrations of the phthalate metabolites measured in the present study were remarkably similar to those measured in urine samples from children living in countries distributed over four continents. These similarities reflect the globalization of children's exposure to phthalate containing products.     

Prenatal exposures to phthalates among women in New York City and Krakow, Poland

Experimental evidence has shown that certain phthalates can disrupt endocrine function and induce reproductive and developmental toxicity. However, few data are available on the extent of human exposure to phthalates during pregnancy. As part of the research being conducted by the Columbia Center for Children's Environmental Health, we have measured levels of phthalates in 48-hr personal air samples collected from parallel cohorts of pregnant women in New York, New York, (n = 30) and in Krakow, Poland (n = 30). Spot urine samples were collected during the same 48-hr period from the New York women (n = 25). The following four phthalates or their metabolites were measured in both personal air and urine: diethyl phthalate (DEP), dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and butyl benzyl phthalate (BBzP). All were present in 100% of the air and urine samples. Ranges in personal air samples were as follows: DEP (0.26-7.12 microg/m3), DBP (0.11-14.76 microg/m3), DEHP (0.05-1.08 microg/m3), and BBzP (0.00-0.63 microg/m3). The mean personal air concentrations of DBP, di-isobutyl phthalate, and DEHP are higher in Krakow, whereas the mean personal air concentration of DEP is higher in New York. Statistically significant correlations between personal air and urinary levels were found for DEP and monoethyl phthalate (r = 0.42, p < 0.05), DBP and monobutyl phthalate (r = 0.58, p < 0.01), and BBzP and monobenzyl phthalate (r = 0.65, p < 0.01). These results demonstrate considerable phthalate exposures during pregnancy among women in these two cohorts and indicate that inhalation is an important route of exposure.     

Phthalates in indoor dust and their association with building characteristics

In a recent study of 198 Swedish children with persistent allergic symptoms and 202 controls without such symptoms, we reported associations between the symptoms and the concentrations of n-butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) in dust taken from the childrens' bedrooms. In the present study we examined associations between the concentrations of different phthalate esters in the dust from these bedrooms and various characteristics of the home. The study focused on BBzP and DEHP because these were the phthalates associated with health complaints. Associations have been examined using parametric and nonparametric tests as well as multiple logistic regression. For both BBzP and DEHP, we found associations between their dust concentrations and the amount of polyvinyl chloride (PVC) used as flooring and wall material in the home. Furthermore, high concentrations of BBzP (above median) were associated with self-reported water leakage in the home, and high concentrations of DEHP were associated with buildings constructed before 1960. Other associations, as well as absence of associations, are reported. Both BBzP and DEHP were found in buildings with neither PVC flooring nor wall covering, consistent with the numerous additional plasticized materials that are anticipated to be present in a typical home. The building characteristics examined in this study cannot serve as complete proxies for these quite varied sources. However, the associations reported here can help identify homes where phthalate concentrations are likely to be elevated and can aid in developing mitigation strategies.