超声辅助-高分子表面活性剂增强乳化微萃取测定水中多种痕量芳香胺

建立了超声辅助-高分子表面活性剂增强乳化微萃取测定水中痕量2,4,5-三甲基苯胺、3,3'-二氯联苯胺以及4-氨基偶氮苯等8种芳香胺的测试方法。对分散液相微萃取的条件进行了优化,实验得到的最佳萃取条件为：萃取剂为二氯乙烷,萃取剂的体积为150μL,活性剂为海藻酸钠,其浓度为0.20 g/L,超声时间为1 min,pH=7.0,盐浓度为3%。在优化实验条件下,测得3,3'-二氯联苯胺的线性范围为0.1~200μg/L,2,4,5-三甲基苯胺等5种芳香胺为0.3~200μg/L,4-氨基偶氮苯等2种芳香胺为0.5~200μg/L,相关系数为0.9961~0.9997,检出限为0.08~0.3μg/L,日内精度RSD<10.3%,日间精度RSD<11.9%。实际水样加标实验表明,本方法可用于不同基质水样中的芳香胺的测定。与常规活性剂增强的超声辅助分散乳化微萃取相比,本方法使用的活性剂为水溶性高分子表面活性剂,无污染且不溶于萃取试剂,可扩展分析仪器的范围;与其它固相萃取方法相比,本方法萃取时间更短,操作更简单,费用更低。     

离子液体-液相微萃取-高效液相色谱法测定纺织品中芳香胺

建立了一种基于1-丁基-3-甲基咪唑六氟磷酸盐离子液体的溶剂棒液相微萃取样品前处理技术,结合高效液相色谱法分析染色纺织品中源于禁用偶氮染料的8种致癌芳香胺的方法。考察了有机萃取溶剂、给出相pH值、搅拌速度、盐效应和萃取时间的影响,确定了以正辛醇为有机萃取溶剂,离子液体为接收相,给出相pH值为10并添加饱和NaCl溶液,搅拌速率为1000 r/min,萃取时间为40 min的芳香胺优化萃取条件。方法的线性范围宽,相关系数r>0.9986;检出限为0.014~2.1μg/L(S/N=3);相对标准偏差<4.6%(n=10);回收率为83.2%~91.2%;8种芳香胺的富集倍数在10~270倍之间。本法具有灵敏,萃取效率高,有机溶剂消耗少,操作简单、快捷等特点。     

分散液相微萃取-气相色谱-质谱法快速检测水体中17种芳香胺

建立分散液相微萃取结合气相色谱-质谱快速检测水体中17种芳香胺的分析方法。以乙腈作为分散剂，三氯甲烷作为萃取剂，将萃取剂和分散剂快速注入水样形成乳浊液体系，涡旋辅助萃取，经高速离心后，取下层有机相分析。采用SIM模式进行检测，根据保留时间定性，内标法定量。17种芳香胺的质量浓度在5.0～200μg/L范围内与对应色谱峰面积和内标峰面积的比值线性相关，相关系数均大于0.997，方法检出限为0.025～0.049μg/L。实际水样平均加标回收率为77.2%～114%，测定结果的相对标准偏差为2.6%～16.5%(n=6)。该方法可应用于水体中芳香胺的高效定量分析。     

浊点萃取-气相色谱-质谱法测定水中9种芳香胺类化合物

本研究基于以曲拉通X-114(Triton X-114)为萃取剂的浊点萃取技术和气相色谱-质谱法,建立了一种高效、高灵敏度的水体中9种芳香胺(2-氯胺、3-氯胺、4-氯胺、2-硝基苯胺、3-硝基苯胺、4-硝基苯胺、1-萘胺、2-萘胺和4-氨基联苯)的检测方法。采用单因素优化法对影响提取效果的重要因素进行了优化。采用气相色谱-质谱对水中9种芳香胺进行定性、定量分析,使用中等极性色谱柱DB-35 MS(30 m×0.25 mm×0.25μm)进行分离,在选择离子模式(SIM)下测定,内标法定量。实验结果表明,9种芳香胺在16 min内能够完全分离,且在各自的范围内线性关系良好,相关系数(R²)均大于0.998。9种芳香胺的检出限(LOD)和定量限(LOQ)分别为0.12～0.48μg/L和0.40～1.60μg/L。选取饮用水源地地表水、近海海水和典型印染行业废水3种类型水体进行加标回收试验,在2个加标水平(2.0、10.0μg/L)下,饮用水源地地表水的加标回收率为81.1%～109.8%,日内精密度为0.7%～5.2%,日间精密度为1.6%～6.2%;近海海水的加...     

固相萃取与超高效液相色谱-质谱联用测定生物样品中芬太尼类物质

建立了固相萃取与液相色谱-质谱(LC-MS)联用分析血清和尿液中10种芬太尼类物质的方法。样品经C18固相萃取(SPE)柱富集分离后,甲醇洗脱,洗脱液采用LC-MS测定。结果表明,尿样基质中,10种芬太尼物质质量浓度在1～100μg/L范围内线性关系良好,相关系数(R~2)大于0.99,检出限(LODs)和定量限(LOQs)范围分别为0.18～0.32μg/L和0.61～1.00μg/L。血清基质中,10种芬太尼含量在2～100μg/L范围内呈现良好的线性关系,其R~2大于0.99,LODs为0.15～0.33μg/L,LOQs为0.50～1.00μg/L。尿样中芬太尼类物质萃取回收率为84.2%～107.7%,血清中萃取回收率为84.7%～99.7%。该方法适用于生物流体中芬太尼类物质的同步测定。     

固相萃取-超高效液相色谱串联质谱法测定水中13种苯胺类化合物

建立了固相萃取-超高效液相色谱串联质谱法测定水中13种苯胺类化合物。样品通过HC-C₁₈固相萃取小柱富集，洗脱后加入内标苯胺-D5进行氮吹浓缩，经HSS T3色谱柱(150 mm×2.1 mm,1.8μm)分离，采用多反应监测扫描模式，以内标法定量。13种苯胺类化合物在0.1～100μg/L(其中3-硝基苯胺为0.2～200μg/L)范围内与特征离子的色谱峰面积线性关系良好，相关系数均大于0.995，方法检出限为0.001～0.006μg/L，平均加标回收率为67.3%～117%，测定结果的相对标准偏差为3.77%～16.9%(n=6)。该法操作简单、稳定性好，能够满足实际水体中13种苯胺类化合物大批量样品分析的需求。     

固相萃取液相色谱编程荧光法测定水质中的4-氟苯胺和联苯胺

建立了固相萃取-液相色谱编程荧光法同时测定水中4-氟苯胺和联苯胺的分析方法。采用Cleanert-PCX阳离子交换固相萃取柱富集水中的4-氟苯胺和联苯胺,用5%氨水-甲醇洗脱,以乙腈-水(内含10 mmol/L的乙酸铵溶液)(20/80,V/V)为流动相,采用液相色谱荧光检测器(4-氟苯胺λex/λem=286 nm/354 nm,联苯胺λex/λem=292 nm/395 nm)分析。4-氟苯胺和联苯胺在2.0~200μg/L和1.0~100μg/L范围内,相关系数均大于0.999,方法检出限分别为0.02μg/L和0.01μg/L。在3个浓度水平加标的平均回收率为75.2%~104%,相对标准偏差在2.1%~7.6%之间。     

在线液膜萃取富集流动注射荧光光度法测定水中痕量苯胺

设计并制造了用作苯胺在线富集的夹板式液膜(SSLM)萃取的流动注射分析装置。磷酸三丁酯用作流动载体,煤油为膜溶剂,试样中苯胺在SSLM萃取单元中得到分离和富集。SSLM萃取体系中pH 3盐酸溶液用作内相,pH 11氢氧化钠溶液用作外相。TBP溶液的适宜浓度为12%,富集时间为10 min,对经富集后pH 11碱性溶液中苯胺所产生荧光的强度进行测定。激发波长eλx为282 nm,发射波长eλm为345 nm,方法的检出限为0.2μg.L-1,苯胺浓度在1~150μg.L-1之间保持线性关系。将此方法用于测定河水中苯胺,根据分析结果算得RSD值均小于5%,回收率在97.6%至100.6%之间。     

分散液相微萃取-气相色谱-质谱法测定环境水样中5种芳香胺的含量北大核心CSCD

向5mL水样中加入0.1g NaCl,溶解后加入50μL三氯甲烷(萃取剂)和300μL丙酮(分散剂),以4 000r·min-1的转速离心2min。采用气相色谱-质谱法测定所得有机相中5种芳香胺的含量,以内标法定量。结果表明:5种芳香胺的质量浓度在一定范围内与其峰面积与内标的峰面积的比值呈线性关系,检出限(3S/N)为0.000 1～0.001 5mg·L-1。以实际空白水样为基体进行加标回收试验,回收率为94.7%～106%,测定值的相对标准偏差(n=6)均小于5.0%。     

基于离子液体的液相微萃取技术对纺织品中22种致癌芳香胺的测定

采用以离子液体为萃取剂的液相微萃取,对纺织品检测国家标准方法(GB/T 17592-2006)中纺织品样品前处理方法进行了改进,建立了纺织品中源于偶氮染料的芳香胺的提取新方法.比较了直接浸入式微萃取和溶剂棒微萃取模式的萃取效果,确定以溶剂棒微萃取为微萃取模式.并优化了液相微萃取条件:以正辛醇为有机萃取溶剂,离子液体为接收相,给出相pH值为10并添加饱和NaCl溶液,搅拌速率为1 000 r/min,萃取时间为40 min.参照纺织品检测国家标准方法,采用高效液相色谱法对所公布的22种致癌芳香胺进行了定性、定量测定.结果表明,该方法的线性范围宽,相关系数r＞0.995 1,检出限(S/N=3)为0.01 ～2.13 μg/L,相对标准偏差小于4.5%( n=8);回收率为82% ～94%,8种芳香胺的富集倍数为5.7 ～270.0.与纺织品检测国家标准方法相比,该方法简单、快速,并显示了较好的富集效果和高的回收率.     

Antibiotic-assisted three-phase liquid-phase microextraction of aromatic amines from aqueous solutions combined with high-performance liquid chromatography

Three-phase liquid-phase microextraction (LLLME) combined with high-performance liquid chromatography (HPLC) equipped with a monolithic column for the analysis of some aromatic amines is described. These compounds were extracted from an aqueous sample (4.0 mL) adjusted to pH 13 with NaOH-NaCl solution (Donor Phase, P₁) into an organic phase (P₂, 150 μL of Benzyl alcohol and ethyl acetate mixture, 2:1) and then back-extracted into a microdrop of aqueous acceptor phase (P3) adjusted to pH 2 with Na₂HPO₄-H₃PO₄ buffer solution. The extraction time T1 (from P₁ to P₂) was 20 min, and T₂ (from P₂ to P₃) was 1 min. Different antibiotics as complexing agents for amines were added to the acceptor phase to improve the extraction time. Factors such as organic solvents, extraction times, addition of antibiotics to the acceptor phase, and stirring rate were optimized. The method was applied to the determination of aromatic amines in waste-water samples. Enrichment factors ranged from 189.0 to 395.5. The linearity range was from 2.5 to 1000 ng/mL, and the detection limits varied from 0.5 to 1.50 ng/mL. Relative standard deviations (%, n = 5) were found (at S/N 3) to be in the range of 1.3–8.5. All experiments were carried out at room temperature, 22 ± 0.5°C. The text was submitted by the authors in English.     

Liquid-liquid-liquid phase microextraction of aromatic amines in water using crown ethers by high-performance liquid chromatography with monolithic column

Liquid-liquid-liquid phase microextraction (LLLME) coupled with high-performance liquid chromatography (HPLC) for the analysis of some aromatic amines is described. These compounds were extracted from 4.0 mL aqueous sample that adjusted to pH 13 with, NaOH-NaCl buffer solution (donor phase, P₁) into an organic phase (P₂) 150 μl benzyl alcohol and ethyl acetate (2:1) and then back extracted into a microdrop of aqueous acceptor phase (P₃), adjusted at pH 2, with Na₂HPO₄-H₃PO₄ buffer solution. The extraction time, T₁ (from P₁ to P₂) was 20 min and T₂ (from P₂ to P₃) was 1 min. Different crown ethers as complexing agents for amines were added to the acceptor phase to improve the extraction time. Factors such as organic solvents, extraction times, and addition of crown ethers to acceptor phase and stirring rate were optimised. The method was applied for determination of aromatic amines in wastewater samples. Enrichment factors ranged from 184.5 to 389.7. The linearity range was from 3 to 1000 ng/ml and the detection limits varied from 0.8 to 1.80 ng/ml. Relative standard deviations (%, n = 5) were found (at S/N 3) in the range of 1.9 to 10.1. All experiments were carried out at room temperature, 22 ± 0.5 °C.     

Liquid-liquid-liquid microextraction of aromatic amines from water samples combined with high-performance liquid chromatography

A simple preconcentration and clean-up liquid-liquid-liquid microextraction of aromatic amines is described in this paper. The compounds were extracted from 2.0 ml aqueous samples (donor phase) into an organic phase, layered on the donor phase, and then back extracted to a microdrop of aqueous receiving phase, suspended in the organic phase. After extraction, the microdrop was injected into the HPLC system directly for analysis. Optimal conditions of the extraction were donor phase (a1): 2 ml of water sample adjusted to pH 13 with NaOH-NaCl; organic phase (o), 150 microl ethyl acetate; and receiving phase (a2) of 2 microl aqueous solution at pH 2.1. The a1-->o extraction time was 15 min and for o-->a2, 30 s. 18-Crown-6 ether, which can complex with amine, was added to the aqueous receiving phase to improve the extraction performance. Enrichment factors ranged from 218 (for 4-nitroaniline) to 378 (for 4-chloro-2-aniline). The calibration curve for these anilines was linear within the range 2.5 ng/ml-2.5 microg/ml (r2=0.998). Detection limits ranged from 0.85 to 1.80 ng/mi (at S/N=3). This procedure can be a selective preconcentration method for aromatic amines present in water samples.     

Ion-exchange chromatography by dicarboxyl cellulose gel.

A new column packing material for ion-exchange chromatography was prepared from cellulose gel by periodate oxidation followed by chlorite oxidation to form spatially paired carboxyl groups (dicarboxyl cellulose, DCC). The carboxyl group was quantitatively introduced to spherical cellulose gel by controlling the extent of oxidation. The DCC gels were examined for their ion-exchange activity for various amines at pH of 2.5-5.5. In this pH range, aromatic amines with acid dissociation constant (pKa) below 2.7 showed no interaction with DCC gels as expected from their lack of protonation. The amines with pKa greater than 3.3, both aromatic and aliphatic, showed strong interaction corresponding to the amount of carboxyl introduced to the gel. However, these amines showed anomalous dependence on pH of the mobile phase, showing a maximum in retention factor at around pH 4. This is in contrast with the nearly constant retention factor of these amines on conventional carboxylated cellulose packing at pH greater than 4.0. The maximum retention factor at pH 4 of DCC gel was 4-5-times greater than that of conventional gel having a similar amount of carboxyls. Since pKa of dicarboxyl groups ranges 3-5 as determined by acid-base titration, the pH giving maximum retention corresponds to the pH at which one of paired carboxyls is dissociated. Possible cause of this anomaly is presented in terms of dissociation state of dicarboxyl groups and its interaction with amines.     

液-液-液微萃取-高效液相色谱法测定人尿液中的美沙酮

建立了液-液-液微萃取与高效液相色谱联用技术快速分析尿样中美沙酮的方法.对有机溶剂种类、体积、样品溶液的pH值、萃取时间、搅拌速度进行了优化.方法的线性范围为0.05～10 mg/L,检出限为0.025 mg/L,相对标准偏差小于5%.     

Preparation of monodispersed vinylpyridine–divinylbenzene porous copolymer resins and their application to high-performance liquid chromatographic separation of aromatic amines

For the separation of aromatic amines, two types of monodispersed porous polymer resins were prepared by the copolymerization of 2-vinylpyridine and 4-vinylpyridine with divinylbenzene in the presence of template silica gel particles (particle size 5 μm), followed by dissolution of the template silica gel in an alkaline solution. The transmission electron micrographs and the scanning electron micrograph revealed that these templated polymer resins have a spherical morphology with a good monodispersity and porous structure. Using these monodispersed polymer resins, the high-performance liquid chromatographic separation of aromatic amines in the mobile phases of pHs 2.0, 2.9, 4.1, 7.2 and 11.7 were carried out. The 2-vinylpyridine–divinylbenzene copolymer resins showed slightly stronger retentions for aromatic amines than the 4-vinylpyridine–divinylbenzene copolymer resins. Under acidic conditions (around pH 2.0), aniline and the toluidines showed no retention on these copolymer resins due to the repulsion between the cationic forms of these amines and pyridinium cations in the stationary phase, whereas less basic aromatic amines or non-basic acetanilide showed slight retentions. Above pH 4.1, the separation of aromatic amines with these polymer resins showed a typical reversed-phase mode separation. Therefore, the separation patterns of aromatic amines are effectively tunable by changing the pH value of the mobile phases. A good separation of eight aromatic amines was achieved at pH 2.9 using the 2-vinylpyridine–divinylbenzene copolymer resins.     

低电渗流毛细管区带电泳分离芳香胺

利用低pH值（pH≤2.0）有效地抑制电渗流,建立起低电渗流毛细管区带电泳(CZE)体系,并分离了7种芳香胺。在此体系中,芳香胺质子化而带正电荷,故采用在毛细管阳极端进样,阴极端检测。实验考察了pH值、电解质浓度对分离的影响,结果发现,当pH＜p K a （p K a =14-p K b ）时,pH值的微小增大会导致芳香胺的迁移时间迅速延长;芳香胺的出峰次序与其p K b 值及分子中含有的胺基和酸性取代基的数目有关,分子中含胺基愈多,p K b 值愈小,出峰愈早;芳香胺含酸性取代基则使峰序滞后。     

Liquid-liquid-liquid microextraction for the enrichment of polycyclic aromatic hydrocarbon metabolites investigated with fluorescence spectroscopy and capillary electrophoresis

The extraction and pre-concentration of phenol, 2-naphthol, and several hydroxyl polycyclic aromatic hydrocarbon (PAH) metabolites were investigated, using liquid-liquid-liquid microextraction (LLLME). The PAH metabolites are a very important class of compounds, and they have not been investigated previously by LLLME. For several of the hydroxyl PAH metabolites, the enrichment factors were small when using LLLME with an alkaline acceptor phase. Changing the acceptor phase to 1-octanol, which gave a two-phase system, improved the enrichment factors significantly for several of the hydroxyl PAH metabolites. For example, the enrichment factor was improved by a factor of 68.5 for 3-hydroxybenzo[a]pyrene. Enrichment factors were investigated as a function of time and stirring rate. At about 55 min the enrichment factor reached a maximum for the two-phase system and at approximately 75 min for the three-phase microextraction system. However, a 30 min extraction time was used for most of the experiments. Also, fluorescence spectroscopy was used to determine the enrichment factors and the mass distribution of the solute between the phases. Fluorescence spectroscopy was very effective in determining the very small concentrations of the solute in the various phases. In addition, capillary electrophoresis and LLLME were combined to demonstrate the substantial enrichment of 2-naphthol by combining these two approaches.     

Liquid–Liquid–Liquid Micro Extraction Combined with CE for the Determination of Rare Earth Elements in Water Samples

A simple method for determination of rare earth elements (REEs) by liquid–liquid–liquid microextraction (LLLME) coupled with capillary electrophoresis and ultraviolet technique was developed. In the LLLME system, 40 mmol L^?1 4-benzoyl-3-methy-1-phenyl-5-pyrazolinone (PMBP) acted as extractant and 4% (v/v) formic acid was used as back-extraction solution. The parameters influencing the LLLME, including the type of the organic solvent, sample pH, formic acid concentration, PMBP concentration, extraction time, volume of organic solvent, stirring rate and phase volume ratio, were investigated. Under the optimized conditions, the detection limits (S/N = 3) of REEs were in the range of 0.19–0.70 ng mL^?1. The developed method was successfully applied to the determination of trace amounts of REEs in water samples.     

Determination of aromatic amines in environmental water sample by hollow fiber-liquid phase microextraction and microemulsion electrokinetic chromatography

A novel method of microemulsion electrokinetic chromatography (MEEKC) coupled with hollow fiber-liquid phase microextraction (HF-LPME) was developed for determination of six aromatic amines including 4-methylaniline, 3-nitroaniline, 2,4-dimethylaniline, 4-chloroaniline, 3,4-dichloraniline and 4-aminobiphenyl. Baseline separation of six aromatic amines was achieved within 8 min by using the microemulsion buffer containing a 10 mM borate buffer at pH 9.0, 0.8% (v/v) ethyl acetate as oil droplets, 60 mM sodium cholate as surfactant, 5.0% (v/v) 1-butanol as co-surfactant. The influence factors relevant to the HF-LPME process were systemically investigated. The obtained enrichment factors were ranged between 70 and 157 in a 30 min extraction time, and the limits of detection ranged between 0.0021 and 0.0048 μg/mL. This purposed method was successfully applied for the analysis of aromatic amines in water sample and the recoveries were ranged from 87.2% to 99.8%.