Detection of 20 phthalate esters in breast milk by GC-MS/MS using QuEChERS extraction method

ABSTRACT

A detection method for 20 different phthalate esters (PAEs) in breast milk analyzed by quick, easy, cheap, effective, rugged, and safe (QuEChERS) clean-up with five internal standards and quantitative GC–MS/MS was established. This method can effectively remove interfering substances such as lipids and fatty acids from breast milk using acetonitrile as the extraction solvent and PSA/C18 as clean-up materials. The 20 PAEs had a linear range of 5.0–500.0 µg/L and recoveries of 83.3–123.3% with RSDs of 0.2–7.6% (n = 6). The method detection limits (LODs) were 0.004–1.3 µg/kg. Dimethyl phthalate (DMP), Diethyl phthalate (DEP), Diisobutyl phthalate (DIBP), Di-n-butyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were detected in the 35 breast milk samples, with median levels of 1.2, 6.8, 7.3, 32.9 and 13.6 μg/kg, respectively, and the concentrations of 20 PAEs ranged between 0.5 and 137.3 μg/kg. This is a fast, simple, sensitive and accurate method for the detection of 20 PAEs in breast milk or dairy products.     

Determination of phthalic acid diesters in human milk at low ppb levels

Phthalic acid diesters (PAE) are omnipresent in the human environment and food is a major contributor to the overall human exposure towards these chemicals. Due to developmental effects, PAE infants’ exposure via human milk has been subjected to a number of analytical studies. These previous studies, however, revealed that normal laboratory blank values are in the range of or even higher than human milk levels due to the presence of PAE in laboratory environments. In order to provide more reliable data on PAE exposure via human milk, the aim of this study was to develop and validate a robust and sensitive analytical method. This should be capable of removing matrix components efficiently and guarantee limits of quantification in the low ppb range. The method development took into account liquid–liquid extraction and selective pressurised fluid extraction (sPFE) as well as chromatography-based clean-up steps. The final method consisted of a liquid–liquid extraction followed by an automated chromatographic clean-up by an sPFE device. After volume reduction the cleaned extracts were analysed by quadrupole GC/MS. Quantification was based on internal standards. An extensive quality assurance and method test programme demonstrated conservatively determined limits of detection and quantification from 0.3 to 10?ng?g^?1 in human milk, with recoveries of internal standards from 50% to 101%. Thus, the method allowed the quality-assured detection of di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DBP), di-2-ethylhexyl phthalate (DEHP), di-allyl phthalate (DAP), benzylbutyl phthalate (BBP) and di-cyclohexyl phthalate (DcHP) in 30 human milk samples provided by 30 volunteers from southern Germany. DiBP, DBP and DEHP were the most commonly detected PAE, with median levels of 1.0, 0.6 and 2.3?ng?g^?1, respectively.     

Analysis of phthalate acid esters in butter and cheese samples using MSPE-GC/MS method: A health risk assessment study

The aim of this study was to evaluate the level of six phthalate acid esters (PAE) and associated health risks in butter and cheese samples, using the magnetic solid-phase extraction with gas chromatography/mass spectrometry (MSPE-GC/MS) technique. In this study, the limit of detection (LODs), limit of quantifications (LOQs) and the recovery percentages were 0.26–1.02, 0.78–3.06 μg/kg and 98.6–102%. The results showed that in all samples, the mean total PAEs was 9.76 ± 2.39 μg/kg (in the range of 6.33–14.49 μg/kg) and the average of Bis (2-ethylhexyl)phthalate (DEHP) was 2.9 ± 0.88 μg/kg (in the range of 1.84–4.24 μg/kg), which is lower than the standard level (EFSA set PAE standard levels between 0 and 50 μg/kg in food and US Environmental Protection Agency (EPA) set 6 μg/L for DEHP in drinking water). Moreover, the average total PAEs in all butter samples were 11.52 ± 2.03 μg/kg (in the range of 7.82–14.49 μg/kg) and the average of DEHP was 3.53 ± 0.73 μg/kg (in the range of 2.05–4.24 μg/kg) and the average total PAEs in all cheese samples were 8.00 ± 1.02 μg/kg (in the range of 6.33–9.91 μg/kg) and the average of DEHP was 2.26 ± 0.43 μg/kg (in the range of 1.84–3.04 μg/kg). The rank order of the estimated THQ (target hazard quotient) values based on the 95% percentile (in all samples) was DEHP > DBP (dibutyl phthalate) > BBP (butylbenzyl phthalate) > DEP (diethyl phthalate). The ILCR (Incremental Life Cancer Risk) assessment found that phthalates (DEHP) in dairy product samples are not of concern to humans. Finally, since the amount of these pollutants was less than the existing standards, it can be concluded that it does not pose any danger to Iranian consumers.     

QuEChERS结合GC-MS法快速检测酿酒玉米中14种邻苯二甲酸酯类塑化剂

建立了QuEChERS结合气相色谱-质谱法(GC-MS)快速检测玉米中14 种邻苯二甲酸酯类塑化剂(PAEs)的方法。样品经乙腈溶液提取,无水硫酸镁和氯化钠盐析后,经N-丙基乙二胺(PSA)填料、十八烷基键合硅胶(C₁₈)及石墨炭黑(GCB)净化,采用选择离子模式,外标法定量。结果表明:14 种PAEs在1~500 μg/L范围内,采用基质匹配法绘制标准曲线,线性良好,相关系数在0.9945~0.9995之间;在15、150、500 μg/kg的加标水平下,平均回收率为80.0%~109.8%,相对标准偏差均小于9.0%;检出限(S/N=3)与定量限(S/N=10)分别为0.1~2.5和0.13~5.0 μg/kg。将该方法应用于6 个不同产地的玉米原料检测,结果显示:样品中检出邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二异丁酯、邻苯二甲酸二丁酯和邻苯二甲酸二(2-乙基)己酯此5种塑化剂,且塑化剂含量均低于国标限量标准。该方法高效、快速、灵敏度高,适合于玉米样品的日常监测。     

Evaluation of Phthalic Acid Esters in Fish Samples Using Gas Chromatography Tandem Mass Spectrometry with Simplified QuEChERS Technique

Phthalic acid esters (PAEs) have become an important food safety concern due to their lipophilic properties and propensity to accumulate in adipose tissue in edible fish. In this study, a simple, sensitive, and accurate analytical method was successfully established for simultaneous determination of 19 PAEs in fish samples using gas chromatography coupled with tandem mass spectrometry (GC–MS/MS). A simplified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure was applied for sample preparation, and the Plackett-Burman factorial design was utilized for optimizing extraction parameters. The calibration curves were linear in the range 0.01–0.5 mg/kg for all of the analyzed PAEs, and the limits of quantification (LOQs) were 0.05–20 μg/kg which are much lower than those in previous reports. The average spiked recoveries ranged from 71.2 to 116.3%, with relative standard deviations (RSDs) of 3.9 to 16.2% (n?=?6). Finally, the method was applied to analyze 60 real fish samples taken from Shanghai Municipality, China, and the diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), and bis(2-ethoxyethyl)phthalate (DEHP) were found in almost all fish samples tested in this study. The present study demonstrated that the established method was suitable for market surveillance of 19 PAE residues in fish samples.     

超低温冷冻除脂-气相色谱串联质谱法检测食用植物油中21种邻苯二甲酸酯

建立了超低温冷冻除脂-气相色谱串联质谱(GC-MS/MS)检测食用植物油中21种邻苯二甲酸酯(PAEs)的新方法。样品用乙腈提取,经超低温(-80℃)冷冻10 min除脂,再经减压浓缩,以正己烷复溶,采用GC-MS/MS多反应监测模式进行测定。结果表明,在考察浓度范围(1~1000 ng/mL)内21种PAEs均呈现良好线性,相关系数均大于0.999,检出限为0.10~8.52 μg/kg,定量限为0.32~28.40 μg/kg,加标回收率为74.31%~116.62%,相对标准偏差为1.21%~17.82%。对市售7类19个油样的抽样检测,显示邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二异丁酯(DIBP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸丁基苄基酯(BBP)、邻苯二甲酸(2-丁氧基)乙酯(DBEP)、邻苯二甲酸二正庚酯(DHP)、邻苯二甲酸二(2-乙基己)酯(DEHP)和邻苯二甲酸二正辛酯(DNOP)共9种PAEs被检出,其中DMP、DBP、DBEP、DHP和DEHP检出率均大于90%,含量范围为105.57~2156.76 μg/kg。该方法操作简便,成本低,可用于食用植物油中PAEs的有效测定。     

Occurrence and air-sea exchange of phthalates in the Arctic

Air and seawater samples were taken simultaneously to investigate the distribution and air-sea gas exchange of phthalates in the Arctic onboard the German Research Ship FS Polarstern. Samples were collected on expeditions ARK XX1&2 from the North Sea to the high Arctic (60 degrees N-85 degrees N) in the summer of 2004. The concentration of sigma6 phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-i-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBP), and diethylhexyl phthalate (DEHP)) ranged from 30 to 5030 pg L(-1) in the aqueous dissolved phase and from 1110 to 3090 pg m(-3) in the atmospheric gas phase. A decreasing latitudinal trend was present in the seawater and to a lesser degree in the atmosphere from the Norwegian coast to the high Arctic. Overall, deposition dominated the air-sea gas exchange for DEHP, while volatilization from seawater took place in the near-coast environment. The estimated net gas deposition of DEHP was 5, 30, and 190 t year(-1) for the Norwegian Sea, the Greenland Sea, and the Arctic, respectively. This suggests that atmospheric transport and deposition of phthalates is a significant process for their occurrence in the remote Atlantic and Arctic Ocean.     

Determination of phthalates in raw bovine milk by gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS) and dietary intakes

Low levels of phthalates, including di(2-ethylhexyl) phthalate (DEHP), in raw bovine milk were determined using gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS). A fast and convenient process of sample treatment combined with TOF-MS analysis (medium resolution >5000), yielded good recoveries (85–125%) and low limits of detection (<0.002 mg kg^?1). The most commonly used phthalate, DEHP, was found in 15 out of 30 samples monitored in this study. DEHP concentrations in raw milk ranged from not detected to 0.154 mg kg^?1, and the mean concentration was 0.057 mg kg^?1. The dietary intake of DEHP was about 0.004 mg kg^?1 body weight day^?1 if a child (24 months, 13 kg body weight) drinks 1 L day^?1 of milk that contains the mean concentration of DEHP found in raw milk. The estimated dietary intake corresponded to 8% of the European Union tolerable daily intake (TDI) of 0.05 mg kg^?1 body weight day^?1. Dimethyl phthalate (DMP) and di-n-butyl phthalate (DBP) were found from two and 20 samples, respectively, at low levels. Diethyl phthalate (DEP), butylbenzyl phthalate (BBP), and di-n-octyl phthalate (DnOP) were not found in any of the samples.     

气相色谱-质谱联用法直接测定植物油料中邻苯二甲酸酯类塑化剂

建立有机溶剂萃取、N-正丙基乙二胺（N-(n-propyl) ethylenediamine,PSA）玻璃固相萃取柱净化、内标法定量、气相色谱-质谱法直接测定植物油料中邻苯二甲酸二甲酯（dimethyl phthalate,DMP）、邻苯二甲酸二乙酯（diethyl phthalate,DEP）、邻苯二甲酸二异丁酯（di-iso-butyl phthalate,DIBP）、邻苯二甲酸二丁酯（dibutylphthalate,DBP）、邻苯二甲酸丁基苄基酯（butyl benzyl phthalate,BBP）、邻苯二甲酸二（2-乙基）己酯（di(2-ethtlhexyl) phthalate,DEHP）和邻苯二甲酸正辛酯（di-n-octyl phthalate,DNOP）7 种邻苯二甲酸酯的方法。该方法在0.01～2.0 mg/L范围内具有良好的线性关系,相关系数R2在0.999 8～1.000 0之间,仪器检出限（RSN=3）为0.01～0.02 μg/L,定量限（RSN=10）为0.03～0.06 μg/L。7 种目标物在0.1、0.5、1.0 mg/kg的加标水平下平均回收率为77.2%～98.8%,相对标准偏差为0.62%～9.37%（n=6）。采用本方法对不同种类、不同产地的76 个植物油料样品中7 种邻苯二甲酸酯类塑化剂含量进行测定。结果表明：所有受检植物油料样品中均检出DBP和DEHP,范围分别为（0.015±0.002）～（0.584±0.012） mg/kg和（0.085±0.006）～（2.334±0.016） mg/kg,检出率均为100%（76/76）;DIBP、DEP、DMP、BBP、DNOP检出率分别为98.7%（75/76）、64.5%（49/76）、63.2%（48/76）、32.9%（25/76）、5.3%（4/76）。17 个油料样品中DBP含量超出国家标准限量（≤0.3 mg/kg）,超标率为22.4%;1 个油料样品中DEHP含量超出国家标准限量（≤1.5 mg/kg）,超标率为1.3%。     

GC-MS/MS法测定不同香型白酒中邻苯二甲酸酯类的含量分析

采用气相色谱-三重四极杆串联质谱法（GC-MS/MS）建立了邻苯二甲酸酯（PAEs）的检测方法,并对12种不同香型白酒中的18种PAEs塑化剂的含量进行了测定。结果表明,18种PAEs的分离效果良好,检出限为0.001～0.428 mg/kg,定量限为0.003～1.426 mg/kg。邻苯二甲酸二异壬酯（DINP）的线性范围为0.403～20.150 μg/mL,其余17种PAEs的线性范围为0.020～1.106 μg/mL,相关系数（R2）均＞0.999,精密度试验结果相对标准偏差（RSD）均＜10%,回收率为82.99%～115.25%;白酒样品检出塑化剂的种类主要为邻苯二甲酸二异丁酯（DIBP）、邻苯二甲酸二正丁酯（DBP）及邻苯二甲酸二（2-乙基）己酯（DEHP）,含量分别在0.18～1.53 mg/kg、0.27～1.36 mg/kg、0.18～1.86 mg/kg,其中兼香型白酒样品的DBP含量为1.36 mg/kg,超出国标规定限值。在凤香型白酒样品和馥郁香型白酒样品中检出邻苯二甲酸二甲酯（DMP）,含量分别为0.53 mg/kg、0.45 mg/kg,在药香型白酒样品中检出邻苯二甲酸二正辛酯（DNOP）,含量为1.42 mg/kg,其余均未检出。     

QuEChERS-液相色谱串联质谱法测定鲜菜类调味品中10种杀菌剂残留

建立鲜菜类调味品中10种杀菌剂的QuEChERS-液相色谱串联质谱测定方法,并优化QuEChERS前处理方法和液相色谱-三重四级杆质谱联用仪的色谱、质谱条件。样品经QuEChERS方法提取和净化后,以乙腈（0.05%甲酸）-水（0.05%甲酸）为流动相,梯度洗脱,经Agilent SB-Aq色谱柱（3.0 mm×100 mm,1.8 μm）分离后,采用三重四极杆串联质谱仪,电喷雾离子源（ESI）,多反应监测（MRM）正离子模式进行检测。结果表明,10种杀菌剂在测定范围内相关系数R2均＞0.999,检出限为0.2～0.6 μg/kg,加标回收率为73.0%～104.7%,精密度试验结果相对标准偏差（RSD）为1.9%～9.8%。该方法具有操作简便、灵敏、准确的特点,适用于鲜菜类调味品中10种杀菌剂的测定。     

固相萃取- 气相色谱法测定食品包装材料中邻苯二甲酸酯类物质

建立采用固相萃取-气相色谱法同时分析检测邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二环己酯(DCHP)、邻苯二甲酸丁基苄基酯(BBP)和邻苯二甲酸二-2-乙基己酯(DEHP)4种邻苯二甲酸酯类物质的方法。研究塑料包装材料中邻苯二甲酸酯类在水、65%乙醇、4%乙酸、正己烷4种模拟液中的溶出及利用固相萃取技术对浸出液进行富集的情况,考察气相色谱操作条件对4种邻苯二甲酸酯类物质分离的影响。结果表明,该方法具有良好的线性相关性,线性相关系数在0.9986～0.9994之间;回收率在80.63%～95.50%之间;DBP、BBP、DCHP和DEHP的检测限分别是0.050、0.010、0.055μg/mL和0.012μg/mL。该方法样品预处理简便,测定方法灵敏、可靠,可用于食品包装材料中邻苯二甲酸酯类的监测。     

一步式QuEChERS方法结合高效液相色谱-串联质谱法测定牛肉中25种磺胺类药物残留

建立了一种基于一步式QuEChERS自动提取和净化的技术,结合高效液相色谱-串联质谱（high performance liquid chromatography-tandem mass spectrometry, HPLC-MS/MS）同时检测牛肉中25种磺胺类药物残留的检测方法。样品经1%乙酸-乙腈提取,以C₁₈、PSA和无水硫酸镁为净化吸附剂,采用一步式QuEChERS自动化前处理设备提取、净化、离心,经C₁₈色谱柱进行分离,以0.2%甲酸甲醇?0.2%甲酸水（含2 mmol/L乙酸铵）为流动相梯度洗脱,ESI正离子模式扫描,多反应监测（Multi-reaction monitoring, MRM）测定,外标法定量。结果表明,所有化合物在0.1~20 μg/L的浓度范围内线性关系良好,相关系数不低于0.990,检出限（LOD）为0.1~3 μg/kg,定量限（LOQ）为1~10 μg/kg。在1、2和10倍LOQ三个加标浓度水平下,目标化合物的平均回收率范围为70.14%~116.93%,相对标准偏差（RSD）范围为0.95%~13.74%（n=5）。该方法简单快速、准确可靠、可用于检测牛肉中磺胺类药物的残留。     

QuEChERS EMR-Lipid技术结合LC/MS/MS快速筛查与确证猪肉中55种兽药残留

运用QuEChERS Enhanced Matrix Removal(EMR)-Lipid技术作为前处理方法,通过高效液相-三重四极杆质谱联用技术建立猪肉中55种兽药残留的快速检测方法。样品采用5%甲酸乙腈进行提取,经QuEChERS EMR-Lipid净化,氮吹浓缩后的溶液通过Agilent Eclipse Plus C₁₈(150 mm×3.0 mm,1.8 μm)进行分离,在三重四极杆正离子动态多反应监测模式下进行检测,通过保留时间及离子对丰度比进行快速筛查和确证,并采用基质标准曲线定量。结果表明,55种化合物在30 min内完成分离,在1.25~250 ng/mL范围内线性关系良好,相关系数r≥0.998,定量限均为1 μg/kg,在1~100 μg/kg加标回收中,回收率在60.5%~139.5%,RSD在1.0%~20.1%(n=6)。本方法简单、快捷、高效,适用于猪肉中多兽药残留的快速筛查与确证。     

QuEChERS-GC-MS联用法检测大麦中14种邻苯二甲酸酯类塑化剂及基质效应的影响

采用QuEChERS结合气相色谱-质谱联用技术建立检测大麦中14 种邻苯二甲酸酯类（phthalate esters,PAEs）塑化剂的高效、准确方法。样品粉碎、过80 目筛,溶于pH 2的水溶液。采用乙腈提取,无水硫酸镁和氯化钠盐析,经十八烷基键合硅胶（C18）净化,C18/大麦比例为50 mg/g;以提取后添加法对大麦中PAEs检测的基质效应评估。结果表明,大麦基质对PAEs均存在基质增强效应,增强比为41.0%～78.1%,采用基质匹配-标准曲线法能较好消除基质效应的影响,提高定量准确度;14 种PAEs在大麦基质3 个加标水平（15、150 μg/kg和500 μg/kg）的平均回收率为73.8%～120.1%,相对标准偏差均小于10%;检出限（3 倍）与定量限（10 倍）分别为0.1～2.5 μg/kg和0.13～5.0 μg/kg。应用该方法对6 个不同产地的大麦原料检测,结果显示：邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二异丁酯、邻苯二甲酸二丁酯（dibutyl phthalate,DBP）和邻苯二甲酸二（2-乙基）己酯（bis(2-ethylhexyl) phthalate,DEHP）在6 个样品中均有检出,含量存在差异;参照GB 9685-2008《食品容器、包装材料用添加剂使用卫生标准》规定,本次检出的大麦样品中DBP、DEHP含量均低于允许最大残留限量标准。     

Occurrence of phthalate metabolites in human urine from several Asian countries

The occurrence of 14 phthalate metabolites was found in human urine samples collected from seven Asian countries: China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam. Phthalate metabolites were found in all samples, indicating widespread exposure of humans to phthalates in these Asian countries. The highest total (the sum of 14 phthalates) phthalate metabolite concentrations were found in samples collected from Kuwait (median: 1050 ng/mL), followed in decreasing order by samples from India (389 ng/mL), China (234 ng/mL), Vietnam (133 ng/mL), Japan (120 ng/mL), Korea (117 ng/mL), and Malaysia (94.9 ng/mL). The creatinine-adjusted median concentrations of total phthalates for urine samples from Kuwait, India, China, Vietnam, Japan, Korea, and Malaysia were 692, 506, 289, 119, 103, 104, and 169 μg/g creatinine, respectively. Monomethyl phthalate (mMP), monoethyl phthalate (mEP), mono (2-isobutyl phthalate) (miBP), mono-n-butyl phthalate (mBP), and metabolites of di-(2-ethylhexyl) phthalate (DEHP) were the dominant compounds, collectively accounting for >95% of the total concentrations in the samples from the seven countries. The profiles of urinary phthalate metabolite concentrations varied among the samples collected from the seven countries. Urine samples from Kuwait contained the highest concentrations of mEP (median: 391 ng/mL), mBP (94.1 ng/mL), and the metabolites of DEHP (202 ng/mL), whereas samples from China and Japan contained the highest concentrations of miBP (50.8 ng/mL) and mMP (17.5 ng/mL), respectively. mEP was the predominant metabolite in urine samples from India and Kuwait (accounting for 49% of the total), mBP and miBP were the predominant compounds in samples from China (52%), and DEHP metabolites were the predominant compounds in samples from Korea (46%) and Vietnam (52%). Based on the urinary concentrations of mEP, mBP, miBP, and DEHP metabolites of the samples from the seven Asian countries, we estimated daily intake rates of diethyl phthalate (DEP), dibutyl phthalate (DBP), and DEHP. The results indicated that people in the seven Asian countries are exposed to DEP, DBP, and DEHP at levels well below the reference doses (RfD) suggested as unsafe by the U.S. Environmental Protection Agency (EPA). The estimated exposure doses to DEHP in Kuwait, however, were above the RfD recommended by the EPA.     

Risk Assessment of Human Exposure to Bioaccessible Phthalate Esters via Indoor Dust around the Pearl River Delta

There is limited information on the bioaccessible fractions of phthalate esters in indoor dust in order to estimate human exposure. In the present study, workplace dust and settled house dust samples from Hong Kong, Shenzhen, and Guangzhou, the three major cities scattered around the Pearl River Delta (PRD) were collected. Chemical analyses showed that the phthalates in workplace dust ranged from 144 to 1810 μg/g, with dust from shopping malls containing the highest level, and in home dust ranged from 181 to 9240 μg/g. The most abundant phthalate ester found was bis(2-ethylhexyl) phthalate (DEHP) in both workplace dust and home dust, followed by di-n-butyl phthalate (DBP) and di-iso-butyl phthalate (DIBP). Principal Components Analysis (PCA) indicated that indoor dust around PRD showed similar phthalate esters patterns of composition. A significant correlation was observed between total phthalate esters concentrations in home dust and the number of year of house construction (p < 0.05). The oral bioaccessibility of phthalate esters in indoor dust ranged from 10.2% (DEHP) to 32% (DMP). Risk assessment indicated that the dominant exposure routes varied in different phthalate esters exposure profiles and the dermal contact exposure pathway was identified as an important route for indoor DEHP exposure.     

GC-MS法测定白酒塑化剂样品前处理方法的选择与优化

对白酒塑化剂检测过程样品的前处理方法进行选择与优化,考察了酒中乙醇除去方式、进样方式、提取溶剂种类对塑化剂检测的样品前处理影响,并分别采用直接提取、水浴氮吹、净化小柱、固相萃取四种不同的前处理方法,分别考察方法的回收率、精密度、检出限。结果表明,气相色谱-质谱联用法（GC-MS）测定白酒中邻苯二甲酸二丁酯（DBP）、邻苯二甲酸二（2-乙基）己酯(DEHP)、邻苯二甲酸二异壬酯（DINP）的样品前处理较优方法为水浴氮吹去除乙醇、正己烷与乙酸乙酯（比例4∶1）为溶剂,采取萃取进样方式。该法在0.5~10.0 μg/mL范围内DBP、DEHP、DINP线性良好,线性相关系数分别为0.998、0.994、0.977。方法的检出限为0.05 mg/kg,添加量为0.05 mg/kg、0.50 mg/kg、1.00 mg/kg时,平均回收率为95.82%~107.26%,相对标准偏差RSD为2.84%~8.36%（n=6）。     

QuEChERS-超高效液相色谱-串联质谱法测定桑叶中64种农药残留

目的 建立QuEChERS结合超高效液相色谱-串联质谱法测定桑叶中64种农药残留的方法.方法 样品经乙腈提取,应用QuEChERS方法进行净化处理.使用Cortecs T3(2.1 mm×100 mm,2.7μm)色谱柱,用含0.1％(V/V)甲酸溶液(A)和甲醇(B)为流动相进行梯度洗脱,采用电喷雾电离(electr...     

Occurrence of phthalates in different food matrices: A systematic review of the main sources of contamination and potential risks

This systematic review aimed to investigate the occurrence of phthalates (phthalic acid esters [PAEs]) in different food matrices, as well as report the main sources of PAEs in food, the potential risks to the population, and the factors that influence its migration from food contact materials (FCMs) to food. Nineteen PAEs were identified, including di-(2-ehtylhexyl) phthalate (DEHP), dibutyl-phthalate (DBP), benzylbutyl phthalate (BBP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP) in fruits and vegetables, milk and dairy products, cereals, meat, fish, fat and oils, snacks, condiments and sauces, miscellaneous, and baby food. Fifty-seven values of PAEs were above the legal limits of countries. DEHP is the PAE with the highest incidence, with maximum concentrations above the specific migration limit (SML) for milk and dairy products, oils and fats, fish, cereals, condiments and sauces, meat, and fruits and vegetables. The risk of exceeding the tolerable daily intake (TDI) was high for DEHP and DBP in fish, fat and oils, cereals, and milk and dairy products for children and adults. Fat and oils are the most critical food for DEHP, DBP, BBP, and DINP. Comparing the estimated daily intake (EDI) with the TDI, there was a risk for “milk and dairy products” in adults and for “cereal and cereal products” in children concerning DEHP. “Cereal and cereal products” presented a risk in children and adults concerning DBP. The “fat and oils” category presented a risk in children and adults about DBP and DINP. Temperature, contact time between food and the FCM, fat percent, and acidity positively correlate with the PAE's migration. The contamination occurs in many steps of the production chain.