A study of polyethoxylated alkylphenols by packed column supercritical fluid chromatography

Alkylphenol polyethoxylates (APEs) are a widely used group of nonionic surfactants in commercial production. Characterization of the composition of APE mixtures can be exploited for the determination of their most effective uses. In this study sample mixtures contain nonylphenol polyethoxylates and octylphenol polyethoxylates. The separation of individual alkylphenols by ethoxylate units is performed by supercritical fluid chromatography (SFC)-UV as well as normal-phase high-performance liquid chromatographic (HPLC)-UV employing packed columns. The stationary phase and column length are varied in the SFC setup to produce the most favorable separation conditions. Additionally, combinations of packed columns of different stationary phases are tested. The combination of a diol and a cyano column is found to produce optimal results. An advantage of using packed columns instead of capillary columns is the ability to inject large amounts of sample and thus collect eluted fractions. In this regard, fractions from SFC runs are collected and analyzed by flow injection analysis-electrospray ionization-mass spectroscopy in order to positively identify the composition of the fractions. In comparing the separation of APE mixtures by SFC and HPLC, it is found that SFC provides shorter retention times with similar resolution. In addition, less solvent waste is produced using SFC.     

New quality-control materials for the determination of alkylphenols and alkylphenol ethoxylates in sewage sludge

The determination of alkylphenols in sewage sludge is still hindered by the complexity of the matrix and of the analytes, some of which are a mixture of isomers. Most of the methods published in the literature have not been validated, due to the lack of reference materials for the determination of alkylphenols in sludge. Given this situation, the objectives of the present study were to develop a new quality-control material for determining octylphenol, nonylphenol and nonylphenol monoethoxylate in sludge. The material was prepared from an anaerobically digested sewage sludge, which was thermally dried, sieved, homogenized and bottled after checking for the bulk homogeneity of the processed material. Together with the sewage sludge, an extract was also prepared, in order to provide a quality-control material for allowing laboratories to test the measuring step. The homogeneity and 1-year stability of the two materials were evaluated. Statistical analysis proved that the materials were homogeneous and stable for at least 1?year stored at different temperatures. These materials are intended to assist in the quality control of the determination of alkylphenols and alkylphenol ethoxylates in sewage sludge.

二氧化硅/聚苯乙烯复合微球的制备及作为固相萃取填料的研究

以分散聚合法制备了二氧化硅/聚苯乙烯单分散复合微球,以红外光谱、透射电镜(TEM)、扫描电镜(SEM)等手段对其进行了表征。以合成的二氧化硅/聚苯乙烯作为固相萃取填料制作固相萃取小柱。通过固相萃取与液相色谱联用,测定了水中邻硝基酚、间硝基酚、对硝基酚和辛基酚、壬基酚,考察了固相萃取条件对固相萃取柱性能的影响,选择了最佳的色谱分离条件。结果表明,自制固相萃取小柱对水中硝基酚、烷基酚的萃取率高,与HPLC联用测定结果重现性好,邻硝基酚、间硝基酚、对硝基酚、辛基酚、壬基酚的最低检出限分别为0.90、0.72、0.62、0.38和0.41μg/L。     

Determination of Alkylphenols Originated from Alkylphenol Ethoxylates by Cleavage Treatment Combined with GC-MS

A chemical cleavage technique was developed for the determination of alkylphenol ethoxylates (APEOs) in environmental samples involving the conversion of APEOs to alkylphenols (APs). Aluminum triiodide (AlI₃) and trimethylsilyl iodide were selected as cleavage reagents and the former was found to be highly reactive and suitable. With AlI₃ as cleavage reagent, nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs) were equivalently converted to the corresponding origins—nonylphenol (NP) and octylphenol (OP), which were detected by gas chromatography—mass spectrometry (GC-MS). The cleavage process was completed under refluxing condition. Water and methanol influenced the cleavage reaction significantly and should be removed prior to the cleavage reaction. The analytical approach was applied for the estimation of APEOs contents in wastewater by normalizing to APs and presented satisfactory recovery and reproducibility. This cleavage technique provides a common and reliable means to assess the environmental significance of samples contaminated by APEOs based on the presence of APs.     

Development and validation of a method for the determination of trace alkylphenols and phthalates in the atmosphere

An analytical method has been developed for the simultaneous extraction and determination of trace tertiary octylphenol (t-OP), technical nonylphenol isomers (NP), nonylphenol monoethoxylate isomers (NP1EO) and seven phthalates in the atmosphere using gas chromatography-mass spectrometry (GC-MS). High volume samples were collected using a high-volume pump equipped with a PUF/XAD-2 column for air and glass fiber filter for particles. The detection limits of the method for alkylphenols (APs) and the phthalates ranged from 0.0006 to 0.034 ng m⁻³ in air. The recoveries of t-OP, NP, NP1EO and the phthalates for the entire procedure were satisfactory (>69%). The method was successfully applied to the determination of the analytes in the atmosphere samples collected over land and the ocean. The concentrations of t-OP, NP, NP1EO showed decline trends from land to the open sea, and the phthalates present over land and the North Sea were comparable. It is suggested that the atmosphere is a significant pathway for the transport of alkylphenols and the phthalates in the environment.     

凝胶过滤色谱-串联质谱法测定纺织品中的烷基酚聚氧乙烯醚

建立了纺织品中烷基酚聚氧乙烯醚的凝胶过滤色谱-串联质谱(GFC-MS/MS)分析方法。纺织品样品采用加速溶剂萃取法,以无水乙醇为提取溶剂进行提取,提取液经Sep-Pak Carbon/NH2石墨化碳黑/氨基复合型固相萃取柱净化。烷基酚聚氧乙烯醚经Shodex MSpak GF-310 2D色谱柱(150×2.0 mm)分离后,在多反应监测(MRM)模式下进行串联质谱定性及定量分析。方法对壬基酚聚氧乙烯醚(NPnEO)和辛基酚聚氧乙烯醚(OPnEO)的定量限均为0.2 mg/kg,在0.2～5 mg/kg的3个添加水平范围内,NPnEO的平均回收率为84.2%～93.5%,相对标准偏差(RSD)为3.9%～7.5%;OPnEO的平均回收率为85.5%～96.1%,RSD为3.4%～8.1%。该方法能够满足纺织品中烷基酚聚氧乙烯醚的检测要求。     

Method for the simultaneous determination of the most problematic families of organic pollutants in compost and compost-amended soil

Linear alkylbenzene sulfonates (LAS), nonylphenol ethoxylates (NPE; sum of nonylphenol, nonylphenol monoethoxylate, and nonylphenol diethoxylate), and di-(2-ethylhexyl)phthalate (DEHP) are the most problematic organic pollutants in sludge owing to their high concentrations and the concentration limits of 2,600, 50, and 100 mg/kg, respectively, proposed in the European Union directive draft for land application of sludge. In this paper, an analytical method for the simultaneous determination of the C₁₀, C₁₁, C₁₂, and C₁₃ LAS homologues, the nonylphenolic compounds nonylphenol, nonylphenol monoethoxylate, and nonylphenol diethoxylate, and di(2-ethylhexyl)phthalate in compost and compost-amended soil is proposed. The method is based on sonication-assisted extraction, cleanup by solid-phase extraction, and determination by high-performance liquid chromatography with diode-array and fluorescence detectors. The mean recoveries of LAS, NPE, and DEHP were 83, 87, and 79%, respectively, in compost samples, and 77, 96, and 99%, respectively, in compost-amended soil samples. The limits of detection and quantification in compost samples were lower than 6.77 and 22.3 mg/kg dry matter, respectively, for LAS; lower than 7.34 and 22.8 mg/kg dry matter, respectively, for NPE; and 0.78 and 1.18 mg/kg dry matter, respectively, for DEHP. The limits of detection and quantification in compost-amended soil samples were lower than 0.03 and 0.10 mg/kg dry matter, respectively, for LAS; lower than 0.04 and 0.12 mg/kg dry matter, respectively, for NPE; and 0.03 and 0.10 mg/kg dry matter, respectively, for DEHP. The method was successfully applied to compost and compost-amended soil samples from Seville (south of Spain).     

超高效液相色谱–串联质谱法测定食品接触材料中烷基酚物质迁移量

建立了超高效液相色谱-串联质谱法测定食品接触材料中双酚A、四溴双酚A、壬基酚和辛基酚迁移量的方法。样品经蒸馏水、3%乙酸溶液、10%乙醇溶液、20%乙醇溶液、50%乙醇溶液和异辛烷6种食品模拟物浸泡处理,浸泡液经C18色谱柱分离,以多反应监测(MRM)模式进行定性和定量。检测结果表明:在水基、酸性、酒精类食品模拟物中,双酚A、四溴双酚A、壬基酚、辛基酚的质量浓度均在0.001~0.50μg/mL范围内与其质谱响应值具有良好的线性关系,相关系数均不小于0.9995,方法检出限为0.01~0.25μg/kg,定量限为0.03~0.83μg/kg;在油基食品模拟物中,双酚A、四溴双酚A、壬基酚、辛基酚的线性范围均为0.01~0.50μg/mL,相关系数均不小于0.9989,方法检出限为0.10~2.50μg/kg,定量限为0.33~8.32μg/kg。双酚A、四溴双酚A、壬基酚、辛基酚的加标回收率为87.2%~101.2%,相对标准偏差为1.5%~3.4%(n=6)。该法样品处理步骤简单,准确度高,灵敏度好,可用于食品接触材料中烷基酚类化合物的检测。     

Simultaneous determination of degradation products of nonylphenol polyethoxylates and their halogenated derivatives by solid-phase extraction and gas chromatography-tandem mass spectrometry after trimethylsilylation

An efficient method for the simultaneous determination of the degradation products of nonylphenol polyethoxylates (NPnEOs, n = number of ethoxy units), i.e., nonylphenol (NP), NPnEOs (n = 1-3), nonylphenoxy carboxylic acids (NPnECs, n = 1-2, number of ethoxy units plus an acetate) and their halogenated derivatives (XNP, XNP1EO and XNP1EC; X = Br or Cl), in water samples were developed. After trimethylsilylation with N,O-bis(trimethysilyl)acetamide, all the analytes were determined by gas chromatography-tandem mass spectrometry (GC-MS-MS) with electron ionization (EI). The ion peaks of [M - 85]+ of the derivatives were selected as precursor ions and their product ions showing the highest intensities were used for the quantitative analysis. The instrumental detection limits were in the range from 2.1 to 11 pg. The recoveries of the analytes from the water samples were optimized by using solid-phase extraction (SPE). The deuterated reagents of octylphenol, octylphenol monoethoxylate and octylphenoxyacetic acid were used as the surrogates. The method detection limits (500 ml water sample) using C18 SPE were from 2.5 to 18 ng/l. The recoveries from spiked pure water and the environmental water samples were greater than 78%. The method was successfully applied to environmental samples. Remarkably, the concentrations of the halogenated compounds (CINP, CINP1EO and BrNP1EO) were detected at the hundreds of ng/l levels in the Neya river.     

Isotope dilution gas chromatography with mass spectrometry for the analysis of 4‐octyl phenol, 4‐nonylphenol,and bisphenol A in vegetable oils

By the combination of solid‐phase extraction as well as isotope dilution gas chromatography with mass spectrometry, a sensitive and reliable method for the determination of endocrine‐disrupting chemicals including bisphenol A, 4‐octylphenol, and 4‐nonylphenol in vegetable oils was established. The application of a silica/N‐(n‐propyl)ethylenediamine mixed solid‐phase extraction cartridge achieved relatively low matrix effects for bisphenol A, 4‐octylphenol, and 4‐nonylphenol in vegetable oils. Experiments were designed to evaluate the effects of derivatization, and the extraction parameters were optimized. The estimated limits of detection and quantification for bisphenol A, 4‐octylphenol, and 4‐nonylphenol were 0.83 and 2.5 μg/kg, respectively. In a spiked experiment in vegetable oils, the recovery of the added bisphenol A was 97.5–110.3%, recovery of the added 4‐octylphenol was 64.4–87.4%, and that of 4‐nonylphenol was 68.2–89.3%. This sensitive method was then applied to real vegetable oil samples from Zhejiang Province of China, and none of the target compounds were detected.     

Determination of alkylphenols and alkylphenol polyethoxylates by reversed-phase high-performance liquid chromatography and solid-phase extraction

A simple, accurate and reproducible reversed-phase high-performance liquid chromatography (HPLC) method was developed for the separation and characterisation of alkylphenols (APs) and alkylphenol polyethoxylates (APEOs), using a C18 octadecyl silica (ODS) column. APs and each APEO oligomer were separated successfully within a reasonable time without gradient elution. An excellent resolution was obtained, even for mixtures of APs and low EO number APEOs, which are otherwise difficult to separate using conventional normal-phase HPLC methods. This method, combined with solid-phase extraction, was highly applicable for the simultaneous determination of alkylphenols and alkylphenol ethoxylates in real samples.     

Liquid chromatography fractionation with gas chromatography/mass spectrometry and preparative gas chromatography-nuclear magnetic resonance analysis of selected nonylphenol polyethoxylates

Commercial nonylphenol polyethoxylates, designated as NPnEOs, where n is the number of ethoxy groups, comprise a range of ethoxylate groups. According to the starting material nonylphenol, they may also be composed of a complex mix of isomeric nonyl substituents. In order to study more fully the heterogeneity arising from both the ethoxylate and nonyl groups, a mixture of NPnEOs is first fractionated by normal phase liquid chromatography (NPLC) into separate fractions comprising individual ethoxymers, n. Preparative collection of each early elution ethoxymer fraction allows further separation of different isomeric nonyl group components by using analytical gas chromatography/mass spectrometry (GC/MS). The nonyl isomers are not resolved in the NPLC method. The distribution of the isomeric nonyl side chain of different ethoxymers bears close resemblance with each other, and also with the original nonylphenol starting material, although separation efficiency of the nonyl isomers for each ethoxymer decreases with increasing ethoxymer number. Mass spectrometry of the separated isomers display close similarity for presumed equivalent isomers in each fraction, based on elution order of the nonyl isomers. This suggests that each corresponding peak has the same isomer structure. Mass spectra are interpreted based on branching within the nonyl side chain. Preparative GC coupled with MS and nuclear magnetic resonance spectroscopy elucidated the molecular structure of one of the resolved isomers as 4-(1,3-dimethyl-1-propyl-butyl)-phenol diethoxylate.     

加速溶剂萃取-液相色谱-质谱/质谱法分析动物组织中的壬基酚、辛基酚和双酚A

建立了测定内分泌干扰物质烷基酚、双酚A的液相色谱-电喷雾串联质谱(负离子模式)分析方法,优化了样品前处理方法。以二氯甲烷作提取溶剂,采用加速溶剂萃取法萃取动物组织样品,萃取液用500 mg OASIS氨基固相萃取柱进行浓缩净化。对流动相组分和流动相添加剂对质谱的离子化效率进行了考察,测得3种化合物在高、中、低3个添加水平的回收率为88%~101%,相对标准偏差小于15%;双酚A、壬基酚和辛基酚的方法检出限分别为0.3, 0.05和0.1 μg/kg。对从北京市场上采集的27份动物组织样品进行检测,结果表明壬基酚广泛存在于各种动物源性食品中,检出含量为0.49~55.98 μg/kg,其中鱼肉组织中都检出壬基酚,而且其含量也较高(9.13~55.98 μg/kg)。     

Determination of Xenoestrogens Alkylphenols in Oyster and Snail Tissues by Extractive Steam Distillation and Gas Chromatography‐Mass Spectrometry

A simple and sensitive method is presented for the determination of two well‐known xenoestrogens alkylphenols (4‐tert.‐octylphenol (4‐t‐OP) and 4‐nonylphenol isomers (4‐NPs)) in oysters and snails. The method involves extraction of the sample by a modified Nielson‐Kryger steam distillation extraction, and the alkylphenols were then identified and quantitated by gas chromatography‐mass spectrometry (GC‐MS) in selected ion monitoring (SIM) mode. The quantitation limit of this method was less than 20 ng/g in 0.5 g (dry weight) of the samples. The perfect applicability of the steam distillation extraction method for 4‐t‐OP and 4‐NPs was determined after testing it with spiked and real samples. Recovery of 4‐t‐OP and 4‐NPs in spiked tissue samples was above 88% while relative standard deviation (RSD) ranged from 7 to 14%. 4‐tert.‐octylphenol and 4‐nonylphenol isomers are ubiquitous in oysters and snails with the concentrations of 4‐t‐OP and 4‐NPs ranging from 70 to 820 ng/g and from 210 to 2750 ng/g (dry weight), respectively.     

酚类环境雌激素的分析研究进展

环境中分布或残留的化学物质对人类和野生动物的内分泌系统的不良影响已引起广泛关注。在已发现的数十种环境内分泌干扰物中，壬基苯酚、辛基苯酚、双酚A和2，4－二氯酚等以其相似的结构特征和类雌激素活性逐渐被划分为一类新的分析研究对象，称为酚类环境雌激素。本文综述了这些物质的主要来源和分布及其分析测定的研究进展，重点评述了一些新的分析技术如基体固相分散萃取法（MSPD）、分子印迹聚合物法（MIP）、荧光分子传感法（FMS）和生物识别－化学分析联用法等在上述物质的分析测定中的应用。比较了GC－MS和LC－MS等手段用于分析此类物质的优势和各自的局限性，并展望了这一领域未来的研究发展趋势。本文引用文献共54篇。     

Environmental Determination of Alkylphenol Polyethoxylate Refractory Residues Using Mass Spectrometric Techniques

Abstract

The use of methane chemical ionisation GC/MS gave satisfactory results when applied to environmental analysis of halogenated octylphenol polyethoxylates residues. In addition the selected ion monitoring GC/MS technique has been successfully applied for simulataneous qualitative and quantitative determination of some refractory metabolites of nonylphenol polyethoxylates in secondary sewage effluent and surface waters.     

An analytical method for the simultaneous trace determination of acidic pharmaceuticals and phenolic endocrine disrupting chemicals in wastewater and sewage sludge by gas chromatography-mass spectrometry

This article presents an analytical method based on solid-phase extraction (SPE) and gas chromatography coupled with mass spectrometry for the simultaneous determination of the most frequently used acidic pharmaceutical residues, ibuprofen, diclofenac, naproxen and ketoprofen (KFN), and phenolic endocrine disruptors, bisphenol (BPA), triclosan (TCS), nonylphenol, nonylphenol monoethoxylate and nonylphenol diethoxylate, in wastewater and sewage sludge samples. In the first phase of the study, each compound has been characterized individually and afterwards in mixture as a trimethylsilyl derivative in order to identify the characteristic ions (m/z ratio) constituting the mass spectrum and to choose the ions for quantification and confirmation. Subsequently, derivatization was evaluated by testing different variables such as the volume of the derivatization solvent bis(trimethylsilyl)trifluoroacetamide and the effect of each catalyst, pyridine and 1% trimethyl chlorosilane, in the derivatized solution. For the analysis of wastewater samples, two commercial SPE cartridges, C18 and Oasis HLB, were compared for their extraction efficiency of the target compounds. The key parameter of extraction procedure included the effect of pH (2.5, 5.3 and 7) of the loading solution. For solid samples, parameters such as the extracted biomass, the volume of the extraction organic solvent and the effect of matrix interferences in chromatographic analysis were evaluated. By using C18 cartridges as purification procedure and ultrasound sonication, satisfactory mean relative recoveries with BPA-d16 and meclofenamic acid as surrogates were obtained ranging from 91% to 117% for wastewater and 84% to 107% for sewage sludge samples. Nine-point calibration of the standard mixture was performed by linear regression analysis with a correlation coefficient >0.99 for all the tested compounds. Limits of detection for the developed methods were established between 0.3 (KFN) and 14.8 (BPA) ng L⁻¹, and 15.0 (TCS) and 32.9 (BPA) ng g⁻¹ for wastewater and sewage sludge, respectively. Application to real samples of the wastewater treatment plant in Athens, the capital of Greece, demonstrated the presence of all tested compounds in most of the samples.     

固相萃取净化-正相高效液相色谱测定纺织品中残留的烷基酚和烷基酚聚氧乙烯醚

建立了测定纺织品中烷基酚(AP)和烷基酚聚氧乙烯醚(APnEO)(n2～16)的正相高效液相色谱法。以甲醇为提取溶剂,用索氏抽提法提取纺织品中的AP和APnEO,用正相高效液相色谱法测定,并对提取溶剂、提取方式和净化条件等前处理条件进行优化。该方法的检出限为1.0 mg/kg,回收率为90.4%～104.1%,相对标准偏差为0.64%～4.21%。采用该方法对多种基质纺织品进行检测,可满足残留检测要求。     

Determination of natural and synthetic estrogenic compounds in coastal lagoon waters by HPLC-electrospray-mass spectrometry

A new analytical method was developed for the simultaneous determination of estrogenic compounds of natural (estradiol, estriol, estrone) and synthetic origin, both steroidal (ethinylestradiol, mestranol) and non-steroidal (benzophenone, bisphenol-A, diethylstilbestrol, octylphenol, nonylphenol, nonylphenol monoethoxylate carboxylate), in environmental aqueous samples by high-performance liquid chromatography coupled with ion trap-mass spectrometry via electrospray interface (HPLC-ESI-IT-MS). Quantitative MS detection was performed in the negative mode for all compounds except mestranol and benzophenone, which were detected under positive ion conditions. Very low method detection limits (MDLs), between 0.1 and 2.6?ng/L, were achieved in coastal lagoon water samples, while the developed solid-phase-extraction (SPE) procedure permitted simultaneous recovery of all analytes from spiked water samples with yields >70% (7–11 RSD%), except estriol and benzophenone, which were recovered with 60% (9 RSD%) and 50% (11 RSD%) yields, respectively. The proposed method was applied to the analysis of Venice (Italy) lagoon waters, where average concentrations of selected compounds in the 2.8–33?ng/L concentration range were found.     

液相色谱-串联质谱法同时测定纺织品和食品包装材料中的壬基酚、辛基酚和双酚A

建立了纺织品和食品包装材料中壬基酚、辛基酚和双酚A的液相色谱-串联质谱分析方法。不同类型的纺织品和食品包装材料样品采用加速溶剂萃取法,以无水乙醇为提取剂,在10.3 MPa和120℃下静态循环提取2次,提取液经Supelclean Envi-Carb石墨化碳黑固相萃取柱净化,收集甲醇-二氯甲烷(1∶4,V/V)洗脱液,采用Waters XBridge C18色谱柱,以甲醇-0.1%氨水溶液为流动相,梯度洗脱分离后,在LC/MS/MS多反应监测模式下进行定性与定量分析。壬基酚、辛基酚和双酚A的方法检出限为0.5μg/kg,在0.5～10μg/kg的3个添加水平范围内,纺织品样品的平均回收率为86.9%～92.5%,相对标准偏差均小于9.1%;食品包装材料样品的平均回收率为87.8%～93.0%,相对标准偏差均小于8.8%。本方法准确、快速、灵敏度高,可用于纺织品和食品包装材料的实际检验。