复杂基质样品中邻苯二甲酸酯测定的样品前处理

对不同类型复杂基质样品中邻苯二甲酸酯(PAEs)测定的前处理方法进行了研究。待测样品类型包括沉积物、土壤、悬浮颗粒物、地表灰尘、生物组织、化妆品、皮革、塑料以及近岸/河口海水等复杂基质样品。这些样品中PAEs测定的最常用方法为气相色谱-质谱法(GC-MS),针对该测定方法所需的样品前处理研究集中于待测PAEs的萃取、净化等步骤操作条件的确定。对各种样品基质前处理方法的研究结果表明,二氯甲烷是进行固液萃取时最佳的超声振荡提取溶剂;而对各种复杂基质样品的净化,硅胶则是经济、实用的固相萃取填料;C18是最常用的近岸/河口海水样品中PAEs的预富集填料;一定比例的正己烷与乙酸乙酯混合溶液是适宜的固相萃取洗脱液。优化实验条件下,各种样品基质中PAEs的加标回收率高于58%,方法相对标准偏差(RSD)小于10.5%(n=6);方法对沉积物样品中PAEs的检出限(DL,3σ)最低,在0.3 μg/kg(邻苯二甲酸二丁酯)~5.2 μg/kg(邻苯二甲酸二异壬酯)之间;对近岸/河口海水样品的检出限(DL,3σ)在6 ng/L(邻苯二甲酸二丙酯)~67 ng/L(邻苯二甲酸二异癸酯)之间,能满足上述各类复杂基质样品中16种PAEs测定的需要。     

GC-MS/MS法测定沉积物和生物样品中邻苯二甲酸酯

采用固相萃取(SPE)和QuEChERS技术结合气相色谱-串联质谱(GC-MS/MS)技术,建立了养殖海域沉积物和生物样品中16种邻苯二甲酸酯(PAEs)定量分析方法.沉积物样品以二氯甲烷为提取溶剂,经PSA-Silica固相萃取柱净化,生物样品以乙腈为提取溶剂,经150.0 mg N-丙基乙二胺(PSA)、150.0...     

Micro-determination of total phthalate esters in biological samples by gas-liquid chromatography.

A method was investigated in which all of the phthalate esters in biological samples were determined as phthalic acid by gas-liquid chromatography. The method is based on the separation of phthalate esters from the sample with n-hexane, saponification of the esters with an alkaline ethanolic solution to give phthalic acid, purification of the acid by extraction with diethyl ether and column chromatography using silica gel, and conversion of the acid into bis(2,2,2-trifluoroethyl) phthalate with a 2,2,2-trifluoroethanol solution containing boron trifluoride. The derivative obtained is highly sensitive to an electron-capture detector, giving a sensitivity of 0.1 pg. Biological samples fortified with di(2-ethylhexyl) phthalate at levels of 5-100 ppb were analyzed, with recoveries of 70-100%.     

Heat capacities of some phthalate esters

Isobaric heat capacities C _p in the liquid phase of dimethyl phthalate, diethyl phthalate, dibutyl phthalate, bis(2-ethylhexyl) phthalate, and benzyl butyl phthalate were measured by commercial SETARAM heat conduction calorimeters. Results obtained cover the following temperature range: dimethyl phthalate 283 to 323 K, diethyl phthalate 306 to 370 K, dibutyl phthalate 313 to 447 K, bis(2-ethylhexyl) phthalate from 313 to 462 K, benzyl butyl phthalate from 313 to 383 K. The heat capacity data obtained in this work were merged with available experimental data from literature, critically assessed and sets of recommended data were developed by correlating selected data as a function of temperature. This revised version was published online in August 2006 with corrections to the Cover Date.     

固相萃取-反相高效液相色谱法测定水中的邻苯二甲酸酯

建立了固相萃取-反相高效液相色谱法检测水中3种邻苯二甲酸酯类物质邻苯二甲酸二甲酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二正辛酯的方法. 考察了固相萃取柱、洗脱溶剂、洗脱体积、上样速度以及洗脱速度对萃取效率的影响. 通过综合分析, 选定SupelcleanLC-18 SPE Tube固相萃取柱, 甲醇为洗脱剂, 洗脱体积2 mL, 上样速度为4 mL/min, 洗脱速度为1 mL/min. 在此萃取条件下, 萃取回收率在83.4%～121.2%之间. 邻苯二甲酸二甲酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二正辛酯质量浓度在2～100 mg/L之间均为线性. 经萃取后, 方法的最低检出限分别为邻苯二甲酸二甲酯0.06 μg/L, 邻苯二甲酸二(2-乙基己基)酯0.16 μg/L, 邻苯二甲酸二正辛酯0.08 μg/L. 方法的精密度在10%～15%之间. 应用该方法测定自来水中酞酸酯类化合物的含量, 加标回收率为83.6%～110.2%.     

Elemental analysis of biological matrices using tomographic techniques

Gamma-ray transmission tomography and neutron induced gamma-ray emission tomography (NIGET) where delayed gamma-rays from an activated sample are detected in a tomographic mode, were used to investigate the elemental composition and distribution of a salivary gland stone, nondestructively. Transmission tomography provided information about the distribution of the linear photon attenuation coefficient in the object and showed clearly the two regions of inorganic and organic material in a number of sections through it. In addition it was possible to derive from the data the concentration of Ca and the ratio of Ca to P in the stone. By using NIGET it was shown that the concentration of Ca and Na in the object can be mapped and quantitative measurements of these elements could be obtained in any particular location within the salivary gland stone. The spatial resolution which depends on detector collimation was 1 mm for transimission and 2 mm for emission measurements. Instrumental neutron activation analysis was also used to determine the concentration of five elements in the stone, as a whole.     

Multivariate optimization of a solid-phase microextraction method for the analysis of phthalate esters in environmental waters

A solid-phase microextraction method (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) has been developed for the determination of the six phthalate esters included in the US Environmental Protection Agency (EPA) Priority Pollutants list in water samples. These compounds are dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butylbenzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DOP). Detailed discussion of the different parameters, which could affect the extraction process, is presented. Main factors have been studied and optimized by means of a multifactor categorical design. Different commercial fibers, polydimethylsiloxane (PDMS), polydimethylsiloxane-divinylbenzene (PDMS-DVB), polyacrylate (PA), Carboxen-polydimethylsiloxane (CAR-PDMS) and Carbowax-divinylbenzene (CW-DVB), have been investigated, as well as the extraction mode, exposing the fiber directly into the sample (DSPME) or into the headspace over the sample (HS-SPME), and different extraction temperatures. The use of this experimental design allowed for the evaluation of interactions between factors. Extraction kinetics has also been studied. The optimized microextraction method showed linear response and good precision for all target analytes. Detection limits were estimated considering the contamination problems associated to phthalate analysis. They were in the low pg mL(-1), excluding DEHP (100 pg mL(-1)). The applicability of the developed SPME method was demonstrated for several real water samples including mineral, river, industrial port and sewage water samples. All the target analytes were found in real samples. Levels of DEP and DEHP were over 1 ng mL(-1) in some of the samples.     

固相萃取-气相色谱-串联质谱法测定大葱等蔬菜中23种邻苯二甲酸酯类化合物残留

建立了气相色谱-串联质谱联用(GC-MS/MS)同时测定蔬菜中23种邻苯二甲酸酯类化合物(塑化剂)的方法。蔬菜经乙腈提取,玻璃Florisil固相萃取柱净化,正己烷定容,Agilent DB-5MS UI超高惰性毛细管柱(30 m×0.25 mm×0.25 μm)程序升温分离,MS/MS(选择反应监测模式)分析,外标法定量。考察了大葱等复杂基质蔬菜中邻苯二甲酸酯类化合物的提取和净化方法,并对色谱和质谱条件进行了优化,提出了扣除本底的办法;通过基质加标校准曲线补偿对邻苯二甲酸酯检测的基质效应。23种邻苯二甲酸酯的线性范围除邻苯二甲酸二异壬酯(DINP)、邻苯二甲酸二异癸酯(DIDP)为0.1~5 mg/L外,其余均为0.02~1 mg/L,相关系数(r)除邻苯二甲酸二(2-甲氧基乙基)酯(DMEP)外均大于0.99。方法的检出限(S/N=3)为0.01~0.05 mg/kg,定量限(S/N=10)为0.02~0.1 mg/kg。3个加标水平下目标物的平均回收率为81.3%~104.2%,相对标准偏差(n=6)为3.2%~11.2%。该方法稳定可靠,应用串联质谱很好地消除了基质效应的干扰,灵敏度高,定性定量更为准确,适用于蔬菜中邻苯二甲酸酯类化合物的检测和确证。     

Hollow fiber stir bar sorptive extraction for determination of phthalic acid esters in environmental and biological matrices

The purpose of this paper is to introduce a novel hollow fiber stir bar sorptive extraction for collecting and determining of phthalic acid esters in environmental and biological matrices. Shell–core ZrO₂/SiO₂ composite microspheres and porous C₁₈ silica microspheres were compared as the sorbents, which were loaded in the lumen of a microporous hollow fiber membrane. A thin stainless‐steel wire was also inside of the hollow fiber membrane acting as the magnetic stirrer, thus affording the procedures like stir bar sorptive extraction to perform the active trapping of the analytes. Variables affecting the extraction (salt addition and pH of samples, extraction temperature, and time) and desorption (microwave time and eluted solvents) have been optimized. Under the optimal conditions, good linearity (r > 0.9968) of all calibration curves was obtained in validation experiments. And the limits of quantification ranged from 0.01 to 1000 ng/mL. The recoveries in different matrices were in the range of 64.90–112.60% with relative standard deviations less than 8.60%. The present work demonstrated the applicability of the developed method for the determination of phthalic acid esters in environmental and biological sample, allowing the selective extraction of phthalate esters in complex samples with low consumption of organic solvents and no sample clean‐up.     

Headspace solid-phase microextraction of oil matrices heated at high temperature and phthalate esters determination by gas chromatography multistage mass spectrometry

A solvent-free analytical approach based on headspace solid-phase microextraction (SPME) of oil matrices heated at high temperatures coupled to gas chromatography with mass spectrometry detector (GC-ion trap) has been developed for the determination of phthalic acid esters (PAEs) in oil matrices without sample manipulation. For this study, three fibers, i.e., 85 μm-polyacrylate (PA), 50/30 μm-divinylbenzene-carboxen-polydimethylsiloxane (DVB/CAR/PDMS) and 100 μm-polydimethylsiloxane (PDMS) were tested. Variables affecting the SPME headspace composition such as incubation sample temperature, sample incubation time and fiber exposition time were optimized. The optimal values found were 250 °C for sample incubation temperature and 30 min for incubation and extraction time. PA fiber was not suitable for the lightest polar phthalates which showed poor extraction and repeatability values. PDMS fiber had very poor response for some of the heavier and non-polar phthalates, whereas DVB/CAR/PDMS fiber showed the best response and repeatability values for the majority of the phthalates studied. The main benefit of the analytical method proposed is the absence of sample manipulation and hence avoidance of possible contamination coming from glassware, environment, solvents and samples.     

植物油中邻苯二甲酸酯类化合物的一步萃取方法

为实现植物油中邻苯二甲酸酯（PAEs）的现场快速检测,建立了气液微萃取（GLME）技术并与GC-MS检测技术联用实现了植物油中PAEs的一步萃取检测。GLME方法在气流吹扫-微注射器萃取技术的基础上建立而成。此方法定量取0.1 g植物油样品,利用GLME在5 min内完成PAEs的萃取、净化和浓缩,结合内标法确保了结果的准确性。在大豆油、调和油、橄榄油、香油等4种样品中添加200 μg/kg的15种PAEs,基质加标回收率为60.0%~112.3%,相对标准偏差（RSD）为0.9%~28.4%。该法操作简单、方便,准确度高,重现性好,基质干扰少,适用于现场检测和快速检测,对于保障我国食品安全、构建完整的食品安全检测体系具有重大意义。     

GC/MS法测定室内空气中邻苯二甲酸酯类物质

针对室内空气中日益严重的邻苯二甲酸酯类污染,建立了固相萃取柱采样,GC/MS测定室内空气中16种邻苯二甲酸酯类物质的测试方法,可用于评价室内空气质量。     

New MALDI matrices based on lithium salts for the analysis of hydrocarbons and wax esters

Lithium salts of organic aromatic acids (lithium benzoate, lithium salicylate, lithium vanillate, lithium 2,5‐dimethoxybenzoate, lithium 2,5‐dihydroxyterephthalate, lithium α‐cyano‐4‐hydroxycinnamate and lithium sinapate) were synthesized and tested as potential matrices for the matrix‐assisted laser desorption/ionization (MALDI)‐mass spectrometry analysis of hydrocarbons and wax esters. The analytes were desorbed using nitrogen laser (337.1 nm) and ionized via the attachment of a lithium cation, yielding [M + Li]⁺ adducts. The sample preparation and the experimental conditions were optimized for each matrix using stearyl behenate and n‐triacontane standards. The performance of the new matrices in terms of signal intensity and reproducibility, the mass range occupied by matrix ions and the laser power threshold were studied and compared with a previously recommended lithium 2,5‐dihydroxybenzoate matrix (LiDHB) (Cva?ka and Svato?, Rapid Commun. Mass Spectrom. 2003, 17, 2203). Several of the new matrices performed better than LiDHB. Lithium vanillate offered a 2–3 times and 7–9 times higher signal for wax esters and hydrocarbons, respectively. Also, the signal reproducibility improved substantially, making this matrix a suitable candidate for imaging applications. In addition, the diffuse reflectance spectra and solubility of the synthesized compounds were investigated and discussed with respect to the compound's ability to serve as MALDI matrices. The applicability of selected matrices was tested on natural samples of wax esters and hydrocarbons. Copyright © 2014 John Wiley & Sons, Ltd.