Practical Method for Accurate Determination of Alkylphenol Ethoxylates in Household Detergents by Aluminum Iodide Cleavage Pretreatment Followed by GC–MS

A practical procedure was developed for detecting nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs) in household detergents by gas chromatography–mass spectrometry (GC–MS) with the introduction of a cleavage technique using aluminum iodide (AlI₃) to convert NPEOs and OPEOs to their parent nonylphenol and octylphenol. The reliability of the cleavage process was evaluated using Igepal-210, Triton X-15, Tergitol NP-9, and Triton X-100 as substrates, demonstrating satisfactory efficiency. The effect of the sample matrix on the cleavage process was investigated, and the optimized dose of AlI₃ was estimated. The major advantage of this method is the use of a common analytical tool (GC–MS) for accurate monitoring of APEOs after elimination of the ethoxylate chain, with detection limits of 12.5 mg/kg and 5.0 mg/kg for NPEO₉ and OPEO₉, respectively. Analytical results revealed that NPEOs and OPEOs were found in 12.6 % of 182 household detergents in the concentration range of 18–800 mg/kg.     

Determination of free and ethoxylated alkylphenols in leather with gas chromatography-mass spectrometry

An analytical approach was developed to determine nonylphenol (NP), octylphenol (OP), nonylphenol ethoxylates (NPEO(n)) and octylphenol ethoxylates (OPEO(n)) in leather samples involving the conversion of NPEO(n) and OPEO(n) into the corresponding NP and OP. The four targets were extracted from samples using ultrasonic-assisted acetonitrile extraction. NP and OP in the extracts were directly isolated with hexane and quantitatively determined with 4-n-nonylphenol as internal standard by gas chromatography-mass spectrometry (GC-MS). For NPEO(n) and OPEO(n) in the extracts, they were first converted into NP and OP with aluminum triiodide as cleavage agent, and the yielded NP and OP were determined by GC-MS. The contents of NPEO(n) and OPEO(n) were calculated by normalizing to NPEO(9) and OPEO(9), respectively. This method was properly validated and the real sample tests revealed the pollution significance of leather by NPEO(n) and OPEO(n).     

Determination of chlormequat and mepiquat in pear,tomato, and wheat flour using on-line solid-phase extraction (Prospekt) coupled with liquid chromatography-electrospray ionization tandem mass spectrometry

A new methodology based on pressurized liquid extraction (PLE) followed by LC-MS is presented for the simultaneous and unequivocal determination of alkylphenol ethoxylates (APEOs) and their degradation products, alkylphenols (APs) and alkylphenoxy carboxylates (APECs), in sediment samples. The protocol, applicable to a full range of APEO oligomers and degradation products, permits the sensitive and selective determination of APEOs (nEO = 1-15), APECs (nEO = 0-1) and APs at low ppb levels (LODs = 1-5 microg/kg) in sediment samples. Optimization of the operational parameters of PLE clearly demonstrates that significant thermal losses of APs occur during extraction at elevated temperatures. The loss of octylphenol (OP) at 100 degrees C was 61.2% and of nonylphenol (NP) 40.0%, whereas other compounds were completely recovered. Thus, to avoid losses due to the volatility of alkylphenols, a low extraction temperature should be applied. The conditions that gave the best results for all target compounds were as follows: extraction solvent mixture, methanol-acetone (1:1, v/v); temperature, 50 degrees C; pressure, 1500 p.s.i.; two static cycles. Using PLE and a subsequent clean-up with solid-phase extraction (SPE), the simultaneous extraction of APEOs, APs and APECs from sediment samples was achieved yielding recoveries >70% and producing low MS background noise. The developed methodology was applied on a routine basis to the analysis of alkylphenolic compounds in sediment samples. APEOs and their persistent degradation products were detected in significant concentrations in sediments from Portuguese rivers, especially at sites situated in the proximity of industrial plants (mainly the textile industry). The total concentration of alkylphenolic compounds (APEOs+APs+APECs) ranged from 155 to 2400 microg/kg. Of all the alkylphenolic compounds, NP comprised 40 to 50% with concentrations up to 1172 microg/kg.     

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。     

Dispersive liquid–liquid microextraction applied to isolation and concentration of alkylphenols and their short-chained ethoxylates in water samples

Dispersive liquid–liquid microextraction (DLLME) coupled with high-performance liquid chromatography with fluorescence detector was applied for the determination of alkylphenols and their short-chained ethoxylates in water samples. Development of DLLME procedure included optimisation of some important parameters such as kind and volume of extracting and dispersing solvents. Under optimised conditions 50 μL of trichloroethylene in 1.5 mL of acetone were rapidly injected into 5 mL of a water sample. After centrifuging the organic phase containing the analytes was taken for evaporation with a gentle nitrogen purge and reconstituted to 50 μL of acetonitrile. The aliquot of this solution was analysed with the use of HPLC. For octylphenol (OP) and octylphenol ethoxylates (OPEOs) linearity was satisfactory in the range 8–1000 μg L⁻¹ and for nonylphenol (NP) and nonylphenol ethoxylates (NPEOs) linearity was in the range from 50 to about 3000 μg L⁻¹. Limit of quantitation was 0.1 μg L⁻¹ for OP and OPEOs and 0.3 μg L⁻¹ for NP and NPEOs. Satisfactory recoveries between 66 and 79% were obtained for environmental samples. The results showed that DLLME is a simple, rapid and sensitive analytical method for the preconcentration of trace amounts of alkylphenols and their ethoxylates in environmental water samples.     

Determination of alkylphenols and their short-chained ethoxylates in Polish river waters

A simple and robust analytical method for analysis of octyl- and nonylphenol as well as their short-chained ethoxylates in river water was proposed. Quantification of these analytes was performed by high-performance liquid chromatography with fluorescence detection after isolation using solid phase extraction with polytetrafluoroethylene sorbent. The method allowed one to obtain about 80–100% recovery for octylphenol and its ethoxylates and 70–80% for nonylphenol and its ethoxylates. Also, there was no need for additional sample cleaning before chromatographic analysis. The limit of detection was 0.01?µg?L^?1 for octylphenol and its ethoxylates and 0.03?µg?L^?1 for nonylphenol and its ethoxylates. The proposed method was used for quantitation of octyl- and nonylphenol together with their short-chained ethoxylates. Nonylphenol, nonylphenol mono- and diethoxylates were detected at concentrations ranging from 0.12 to 0.53?µg?L^?1. Octylphenol, octylphenol mono- and diethoxylates were detected in four out of eleven samples at concentrations ranging from 0.03 to 0.17?µg?L^?1. High concentrations of nonylphenol and its ethoxylates were found in the samples, despite the fact that their use in European countries was forbidden several years ago.     

Simultaneous determination of alkylphenol ethoxylates and their biotransformation products by liquid chromatography/electrospray ionisation tandem mass spectrometry

Reversed-phase LC-MS/MS is used to determine major estrogenic alkylphenol ethoxylates (APEOs) and their biotransformation products. It allows the simultaneous analysis of eight APEOs, alkylphenoxy carboxylates (APECs) and alkylphenols (APs) in sewage treatment plant (STP) effluents in the same extract after solid-phase enrichment on polymeric Oasis HLB. As precursor ions, [APEO + NH4]+, [APEC - H]- and [AP - H]- were monitored. Instrumental limits of detection (LOD) were 2-600 pg, corresponding to sample concentrations of 0.04-12 ng l(-1), without correction for overall method recoveries. Matrix-induced signal suppression during electrospray ionisation (ESI) and extraction as well as overall method recoveries were assessed and the suitability of deuterated surrogates as internal standards was evaluated.     

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.     

Determination of alkylphenol and alkylphenolethoxylates in biota by liquid chromatography with detection by tandem mass spectrometry and fluorescence spectroscopy

A quantitative method for the simultaneous determination of octylphenol, nonylphenol and the corresponding ethoxylates (1 to 5) in biota is presented. Extraction methods were developed for egg and fish matrices based on accelerated solvent extraction followed by a solid-phase extraction cleanup, using octadecylsilica or aminopropyl cartridges. Identification and quantitation were accomplished by liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) and compared to the traditional liquid chromatography with fluorescence spectroscopy detection. LC-MS-MS provides high sensitivity and specificity required for these complex matrices and an accurate quantitation with the use of 13C-labeled internal standards. Quantitation limits by LC-MS-MS ranged from 4 to 12 ng/g in eggs, and from 6 to 22 ng/g in fish samples. These methods were successfully applied to osprey eggs from the Chesapeake Bay and fish from the Great Lakes area. Total levels found in osprey egg samples were up to 18 ng/g wet mass and as high as 8.2 microg/g wet mass in the fish samples.     

固相萃取高效液相色谱质谱法测定海水中烷基酚和烷基酚聚氧乙烯醚

建立了固相萃取-高效液相色谱-电喷雾质谱分析海水中辛基酚、壬基酚、辛基酚聚氧乙烯醚和壬基酚聚氧乙烯醚的方法。海水样品经C18固相萃取柱富集净化后,以甲醇-水为流动相,在Hypersil GOLD色谱柱上分离,电喷雾质谱在选择离子监测模式下分析目标化合物,采用外标法定量。结果表明,4种化合物的平均加标回收率为59.6%～104.4%,相对标准偏差(RSD, n=3)为1.0%～13.5%;仪器检出限为0.08～3 μg/L。将本方法用于大连海岸6个采样点海水中辛基酚、壬基酚、辛基酚聚氧乙烯醚和壬基酚聚氧乙烯醚的检测发现,样品中壬基酚和壬基酚聚氧乙烯醚均有检出,且油港和海港附近海水中的含量较高。     

Multi-Target Strategy to Uncover Unexpected Compounds in Rinse-Off and Leave-On Cosmetics

The wide range and complexity of cosmetic formulations currently available on the market poses a challenge from an analytical point of view. In addition, during cosmetics manufacture, impurities coming from raw materials or formed by reaction of different organic compounds present in the formulation may be present. Their identification is mandatory to assure product quality and consumer health. In this work, micro-matrix solid-phase dispersion (μMSPD) is proposed as a multi-target sample preparation strategy to analyze a wide number of unexpected families of compounds including polycyclic aromatic hydrocarbons (PAHs), pesticides, plasticizers, nitrosamines, alkylphenols (APs), and alkylphenol ethoxylates (APEOs). Analytical determination was performed by gas chromatography-mass spectrometry (GC-MS) for the determination of 51 target compounds in a single run, whereas liquid chromatography tandem mass spectrometry (LC-MS/MS) was employed for the analysis of six APs and APEOs. Both methodologies were successfully validated in terms of linearity, accuracy, and precision in leave-on and rinse-off cosmetics. Limits of detection (LODs) were calculated in the low ng g⁻¹, showing their suitability to determine trace levels of impurities and banned compounds with different chemical natures, providing useful tools to cosmetic control laboratories and companies.     

新型毛细管内固相萃取-气相色谱法检测纺织品中烷基酚类物质

建立了毛细管内固相萃取(SPE)-气相色谱(GC)检测纺织品中壬基酚和辛基酚含量的分析方法。通过比较4种性质不同固相萃取剂的萃取效果,筛选出对烷基酚(APs)类物质萃取效果最佳的固相萃取剂,将其作为填充物质制作毛细管内固相萃取柱,将毛细管内固相萃取法与气相色谱联用进行分析检测。最佳固相萃取剂为Abselut NEXUS,毛细管内固相萃取最佳条件为:1.2 μL甲醇和1.2 μL超纯水活化,1.2 μL甲醇洗脱,上样速率是0.4 μL/min。该法在较低浓度范围内呈现良好的线性相关性,对烷基酚的富集倍数约为100倍,对辛基酚和壬基酚的检出限分别为3.7 μg/L和4.5 μg/L,加标回收率分别为85.6%~98.2%和83.8%~95.7%,结果表明,此法能够简捷、迅速、有效地检测出纺织品中残留的烷基酚类物质。     

Immunoenzyme assay of nonylphenol: study of selectivity and detection of alkylphenolic non-ionic surfactants in water samples

Immunoenzyme assay (ELISA) is proposed and characterized for determination of alkylphenol ethoxylates, a primary class of manufactured non-ionic surfactants. The assay is based on the obtained polyclonal antibodies against nonylphenol (NP), the main stable intermediate of the decomposition of nonylphenol ethoxylates. A mixture of non-modified branched isomers of NP was applied as hapten coupled to protein carriers by Mannich reaction with the use of formaldehyde. The proposed ELISA format is based on immobilized NP-(soybean trypsin inhibitor) conjugate as a competitor of antigen molecules contained in the tested sample for binding with specific antibodies indirectly labeled via an anti-species immunoperoxidase conjugate. The developed ELISA allows to reveal NP with the limit of detection about 10 ng ml⁻¹ and NP-related compounds such as octylphenol, alkylphenoletoxylates, alkylphenolcarboxylates and their halogenated derivatives. The ELISA was applied for assaying polluted water samples, namely influents and effluents from different wastewater treatment plants (WWTP) and tap water. ELISA and chromatographic data demonstrate good correlation (r = 0.94), while ELISA gives higher values. Due to endocrine disrupting and other toxic activities of some metabolites of alkylphenolic non-ionic surfactants, the developed assay may be effectively used in ecological monitoring and sanitary control.     

Analysis and occurrence of alkylphenolic compounds and estrogens in a European river basin and an evaluation of their importance as priority pollutants

As a part of a project aiming to assess the potential toxicological effects of contaminants in aquatic ecosystems, the objective of this work was to determine the occurrence of several selected endocrine-disrupting compounds in water and sediment and to estimate the estrogenicity of the water. The study consisted of four sampling campaigns at seven sampling points in the lower Llobregat catchment area (NE Spain). Water and sediment samples underwent chemical target analysis for 19 steroid estrogens and alkylphenols, which are known to be endocrine-disrupting compounds. In this study, the only estrogens detected in the water samples were estrone and estrone-sulfate, which were found at low levels (2–5 ng l⁻¹). The alkylphenolic compound showing the highest concentrations was nonylphenol di-ether carboxylate (NP2EC), which was found at levels up to 30.62 μg l⁻¹ in water samples and 535 ng g⁻¹ in sediment samples. K _d was determined for several alkylphenolic compounds and showed the expected trend of decreasing K _d with increasing polarity. The concentrations of nonylphenol and octylphenol only exceeded the annual average of the European Union’s environmental quality standards (EQS) in one sampling point. However, the calculated estrogenic potential surpassed the expected effect concentration in several sampling points, indicating a potential risk. Therefore, we recommend that future EQS include short-chain alkylphenol ethoxylates and carboxylates.     

Determination of alkylphenols and alkylphenol ethoxylates in sewage sludge: effect of sample pre-treatment

A complete characterization of sewage sludge collected from five biological waste water treatment plants was done to determine physico-chemical parameters, heavy metals and alkylphenols, making special emphasis on sampling, homogenization, and sample pre-treatment. Ultrasonic extraction followed by gas chromatrography coupled with mass spectrometry was used to evaluate the effect of sample pre-treatment (untreated sample, freeze-drying, drying at 40 °C or drying at 100 °C) on the concentration of octylphenol (OP), nonylphenol (NP) and nonylphenol ethoxylates (NP₁EO, NP₂EO). Untreated samples and samples dried at 100 oC gave concentration levels up to 62% and 89% lower, respectively, than freeze-dried samples. In 50% of cases, freeze-dried samples led to significantly higher concentrations than those obtained by drying at 40 °C. Thus, freeze-drying is the recommended sample pre-treatment to prevent possible losses of OP, NP, and NP₁EO. Using this methodology, concentrations detected were from 3.2 to 199 mg kg⁻¹ being NP followed by NP₁EO found in highest concentration. The total concentration of NP and NP₁EO exceeded the limit of 50 mg kg⁻¹ proposed by the draft European directive on sewage sludge in three out of five samples studied. Contrarily, heavy metals were below the legislated values.     

Chemical monitoring and occurrence of alkylphenols, alkylphenol ethoxylates, alcohol ethoxylates, phthalates and benzothiazoles in sewage treatment plants and receiving waters along the Ter River basin (Catalonia, N. E. Spain)

This study presents a quantitative estimation of the analysis and fate of several emerging pollutants, some of them endocrine-disrupting compounds, in surface water samples collected at several locations along the Ter River and two of its tributaries. Influent and effluent waters and particulate matter from five sewage treatment plants (STP) that discharge into these rivers were also studied. The target compounds analyzed were: nonylphenol ethoxylates (NPEO), nonylphenol (NP), octylphenol (OP), bisphenol A (BPA), phthalates, alcohol ethoxylates (AEO) and benzothiazoles. Chemical analysis by liquid chromatography–mass spectrometry using an electrospray interface (LC–ESI–MS) revealed the presence of low amounts (between 0.06 and 17.5 μg L⁻¹) of the target compounds NPE₁₊₂O and NP, which were detected in 100% and 84% of the samples respectively. Maximum concentrations occurred in the STPs associated with the municipalities of Vic and Girona. From the fate and behavior data obtained for the various compounds analyzed in the STP influent and effluent, we can conclude that the STPs are effective at removing large amounts (more than 70%) of the compounds studied from the water.      

Determination of various estradiol mimicking-compounds in sewage sludge by the combination of microwave-assisted extraction and LC-MS/MS

In this work, we present the development and application of a microwave assisted extraction followed by liquid chromatography-tandem mass spectrometry methodology (MAE-LC-MS/MS) for the determination of various estradiol-mimicking compounds in sewage sludge samples. For the purification of the MAE extracts, we have employed a solid phase extraction (SPE) clean-up procedure, previously optimised. The entire method provides recoveries between 71.7% and 103.1%, with relative standard deviation lower than 11.1% and limits of detection ranging from 0.6 to 3.5 ng g⁻¹. The developed method was applied to samples from three wastewater treatment plants (WWTPs) located in Las Palmas of Gran Canaria (Spain), two of which had a conventional activated sludge treatment (AST), whereas the third treatment plant had an advanced membrane bioreactor treatment (MBR). All of the analytes in the study, including (nonylphenol (NP), octylphenol (OP), and some of their ethoxylated chains AP_nEOs (n ≤ 7), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE) and bisphenol-A (BPA)), were found in almost all samples in concentrations ranging from 0.9 to 710.2 ng g⁻¹.     

A simplified method for simultaneous quantitation of alkylphenols and alkylphenol ethoxylates in meat and fish using high-performance liquid chromatography with fluorescence detection

Nonylphenol (NP), octylphenol (OP), nonylphenol monoethoxylate (NP₁EO) and nonylphenol diethoxylate (NP₂EO) are products of the biodegradation of alkylphenol polyethoxylates (AP _n EO) which are used worldwide as detergents and surfactants. NP and OP are categorized as definitely endocrine disruptors. 2,4-Tert-butylphenol (BP) is extensively used for anti-oxidant of rubber and plastics. This work proposed a simple and stable method for simultaneously determining the concentration of NP, OP, BP, n-NP₁EO and n-NP₂EO in meat and fish, without requiring the complex pretreatments of current methods. This study used liquid extraction with acetonitrile and hexane and solid extraction using Florisil, in that order to pretreat samples. The sample solutions were analyzed to identify NP, OP, BP, n-NP₁EO and n-NP₂EO by HPLC with fluorescence detection. The mean recoveries were 85.3?±?3.32% for OP, 87.5?±?6.01% for BP, 90.9?±?4.72% for NP, 86.4?±?4.81% for n-NP₂EO and 90.9?±?4.84% for n-NP₁EO. The average coefficients of variation were about 6%. The method's detection limits were 5.4?ng?g^?1 for OP, 5.2?ng?g^?1 for BP, 8.9?ng?g^?1 for NP, 8.7?ng?g^?1 for n-NP₂EO and 8.1?ng?g^?1 for n-NP₁EO. This work analyzed 5 kinds of usual foodstuffs of meat and fish that are frequently consumed by residents of Taiwan. All of these samples contained NP, but not detectable levels n-NP₁EO. Only salmon was contaminated with n-NP₂EO. The NP level was highest in cod (198.41?±?129.34?ng?g^?1, wet weight). The fried chicken had the highest BP level (48.0?±?41.3?ng?g^?1, wet weight), and the uncooked chicken had the highest OP level (66.6?±?53.0?ng?g^?1, wet weight).     

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。