水产品中酰胺类除草剂及其代谢物的气相色谱-质谱法测定

建立了同时测定水产品中5种酰胺类除草剂(乙草胺、甲草胺、异丙甲草胺、丁草胺、丙草胺)及其代谢物2-甲基-6-乙基苯胺(MEA)、2,6-二乙基苯胺(DEA)的气相色谱-质谱联用(GC-MS)分析方法.样品经二氯甲烷-乙酸乙酯(3:2,体积比)混合溶剂提取,正己烷洗脱后进行GC-MS检测.在优化检测条件下,MEA、DEA...     

利用溶解度参数选择有机溶剂提取土壤中多种有机氯农药

采用基团贡献法计算了提取溶剂（正己烷、二氯甲烷、正己烷—甲醇（体积比4：1)、正己烷—丙酮（体积比1：1)、正己烷—二氯甲烷(体积比1：1))和有机氯农药（o,p′—DDT,o．p′—DDE,o,p′—DDD,α—endosubn,endrin,HCB)的色散溶解度参数(δd)、极性溶解度参数(δp)和氢键溶解度参数(δh),运用溶解度参数的理论筛选有机溶剂提取江西红壤中多种有机氯农药：研究表明正己烷—甲醇（体积比4：1)和正己烷—丙酮（体积比1：1)是提取江西红壤中o,p′—DDT,o,p′—DDE,o,p′—DDD多种有机氯农药的最佳提取溶剂（回收率大于82％),对α—endosulfan,endrin,HCB的提取也能满足检测需要（回收率大于75％)。超声波提取的结果验证了溶解度参数预测的合理性。     

快速溶剂萃取-气相色谱-质谱法同时测定土壤中多环芳烃、六六六和滴滴涕

建立快速溶剂萃取-气相色谱-质谱法同时测定土壤中多环芳烃、六六六和滴滴涕。优化了提取溶剂和洗脱溶剂,采用加速溶剂萃取法处理土壤样品,萃取溶剂为二氯甲烷-正己烷(1∶1)。提取液用氮吹仪浓缩、硅酸镁固相萃取小柱净化,用二氯甲烷-正己烷(3∶7)混合溶剂对固相萃取小柱进行活化和洗脱,流出液净化后氮吹浓缩至1 mL,利用气相色谱-质谱内标法进行分析定量。16种多环芳烃、8种有机氯农药及3种替代物在5.0～500μg/L范围内线性良好,方法检出限为0.000 55～0.000 77 mg/kg,加标回收率为68.2%～112.7%,相对标准偏差为4.3%～10.1%(n=5)。该方法可用于同时测定土壤中多环芳烃、六六六、滴滴涕的含量。     

气相色谱-质谱法测定塑料玩具中多环芳烃

提出了气相色谱-质谱法测定塑料玩具中16种多环芳烃(PAH′s)含量的方法。样品经正己烷超声提取30min后,40℃水浴氮气吹干。用水、甲醇和正己烷-二氯甲烷(3+2)混合溶剂各5mL溶解残渣,过C18固相萃取柱净化,用正己烷-二氯甲烷(3+2)混合溶液洗脱,所得洗脱液过HP-5MS色谱柱分离,电子轰击离子源检测。16种多环芳烃的质量浓度在0.2～4.0mg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.002～0.021mg·kg-1之间。以聚丙乙烯、聚乙烯、聚氯乙烯或丙烯腈-丁二烯-苯乙烯共聚物等4种材质的塑料玩具为基体,进行加标回收试验,回收率在79.6%～95.2%之间。     

同位素稀释三重串联四级杆质谱法测定鱼组织中24种多环芳烃

采用气相色谱-三重串联四级杆质谱联用技术测定了鱼组织中24种多环芳烃(PAHs).将冻干鱼组织样品加入同位素内标后,用加速溶剂萃取法(ASE)进行提取,提取液采用凝胶排阻色谱(GPC)和固相萃取(SPE)联用进行净化.采用二氯甲烷为提取溶剂,100℃下提取,以二氯甲烷作为GPC的流动相,在3.5 mL/min流速下,收...     

气相色谱-质谱法测定核桃壳提取物中化学成分

经粉碎的核桃壳样品两份分别以二氯甲烷-甲醇(93+7)混合溶剂进行索氏抽提和以二氯甲烷-甲醇-水(93+7+100)混合溶剂进行加热回流提取;所得提取液用气相色谱-质谱法进行分析。结果表明:在索氏抽提物中鉴定出34种化合物,在加热回流提取物中鉴定出13种化合物。化合物的主要类型是有机酸和有机酸酯类化合物,其次是醛、酚、醇、酮和萘类化合物等。     

加速溶剂萃取-气相色谱串联质谱法检测沉积物中痕量增塑剂

研究了加速溶剂萃取(ASE)对沉积物中邻苯二甲酸酯类(PAEs)物质的提取效果,建立了快速溶剂萃取/气相色谱-质谱联用(GC/MS)检测沉积物中16种邻苯二甲酸酯类物质的方法。用正己烷和二氯甲烷混合溶剂作为提取溶剂,加速溶剂萃取法萃取沉积物中16种PAEs,再用Florisil层析柱净化,最后用GC/MS对净化后提取液中的PAEs进行定量分析。结果表明:当萃取剂为二氯甲烷-正己烷(1∶1,V/V),萃取温度为80℃时,萃取效率最高,16种PAEs的回收率稳定在81.2%～128.5%之间,相关系数≥0.99,检出限为0.12～0.98 ng/g,相对标准偏差为1.1%～10.8%。加速溶剂萃取法与传统索氏提取法相比,既提高了萃取效率同时又减少了有机萃取溶剂的用量。在检测实际样品时,同时加入3种内标指示剂对方法的性能进行了验证,3种内标的回收率分别为106.0%±18.8%,87.4%±10.8%和81.4%±14.5%,样品中16种PAEs的检出率为100%。前处理方法处理简单,定性与定量分析准确可靠。     

土壤中10种多溴联苯醚的加速溶剂-固相萃取净化方法优化研究

建立了土壤中10种多溴联苯醚(PBDEs)的加速溶剂萃取-固相萃取净化-气相色谱分析测定方法.采用加速溶剂萃取(ASE)技术对土壤中10种PBDEs进行提取,并对4种萃取体系(正己烷、正己烷-丙酮(4∶1,V/V)、正己烷-丙酮(1∶1,V/V)、正己烷-二氯甲烷(1∶1,V/V))进行优化;采用固相萃取(SPE)技术对样品进行净化,制备了10种不同填料的SPE柱,通过洗脱实验和加标回收率实验对各SPE柱的净化性能进行对比筛选.最终优化条件为正己烷-丙酮(4∶1,V/V)体系提取,酸性硅胶柱净化.在优化条件下,10种PBDEs的回收率为74.4％ ～ 125.2％,相对标准偏差为4.4％ ～ 14.4％,方法检出限为0.04～0.22 ng/mL.本方法简单、快速、净化效果较好、重现性和回收率良好,可用于土壤样品中PBDEs的分析.     

非极性溶剂微波萃取-气相色谱-质谱法测定白豆蔻中挥发油成分

提出了非极性溶剂微波萃取-气相色谱-质谱法测定白豆蔻中的挥发油成分的方法。优化的试验条件如下:①微波吸收介质为0.35g石墨粉;②提取溶剂为正己烷;③样品质量与溶剂容积之比为2g比25mL;④提取时间为30min。在气相色谱分离中用DB-5石英毛细管柱为固定相,在质谱分析中采用全扫描检测模式。以α-甲基苯甲醇丙酸酯为内标物。方法用于白豆蔻样品的分析,共鉴定出60种挥发性化学成分,主要化合物为桉油精(70.34%)、β-蒎烯(6.81%)、α-松油醇(3.36%)和α-蒎烯(2.54%)等。     

深共熔溶剂同步提取红景天中红景天苷和酪醇

采用深共熔溶剂(Deep eutectic solvents, DESs)法同步提取红景天中红景天苷和酪醇. 首先, 通过对氢键供体(HBD)、 氢键受体(HBA)及二者摩尔比和DESs含水量等因素的设计优化, 获得了同步提取红景天苷和酪醇的最佳DES为乙二醇-乙酰丙酸(摩尔比为1∶1), 含水质量分数为40%, 记为LAEG-40. 然后, 以LAEG-40作提取溶剂, 对提取方法、 料液比、 提取温度及提取时间等因素进行优化, 获得了最佳提取条件: 采用150 r/min搅拌速率提取, 料液比为1∶12.5(g/mL), 提取温度60 ℃, 提取时间65 min. 在此条件下LAEG-40对红景天苷的提取率可达(18.1268±0.1667) mg/g, 酪醇提取率可达(1.5608±0.0240) mg/g. 而在相同条件下, 以水和乙醇作为提取溶剂, 红景天苷提取率分别为(15.1221±0.1342)和(16.3425±0.0897) mg/g, 酪醇提取率分别为(1.1120±0.0389)和(1.1923±0.0423) mg/g, 可见LAEG-40的提取效果明显高于传统溶剂. 研究结果表明, LAEG-40是一种绿色、 高效的红景天苷和酪醇同步提取溶剂, 可用于替代传统溶剂.     

Extraction of organic acids by ion-pair formation with tri-n-octylamine : Part 4. Influence of organic phase composition

Synthetic food dyes are extracted by ion-pair formation with tri-n-octylamine. Mixed organic phases are used, consisting of mixtures of hexane with one of the following solvent modifiers: chloroform, dichloromethane, methyl isobutyl ketone, butyl acetate or pentanol. Logarithmic plots of the distribution ratio versus the volume fracton of the solvent modifier are linear for dichloromethane, chloroform and pentanol. The efficiency of the solvents is classified as follows: dichloromethane > pentanol > chloroform > methyl isobutyl ketone > butyl acetate > hexane. The addition of pentanol to chloroform provides nearly quantitative recovery for hydrophilic solutes.     

韭菜有机溶剂提取液的气相色谱-质谱分析及其对香蕉枯萎病菌的抑制作用研究

采用气相色谱-质谱法对韭菜茎和叶的石油醚、三氯甲烷、二氯甲烷、丙酮、乙酸乙酯有机溶剂提取液进行了检测.结果表明:有机溶剂提取液中有二甲基二硫、二甲基三硫、甲基甲烷硫代磺酸盐、二甲基酯硫磺酸、甲基2-丙烯基二硫及杂环等多种含硫化合物,另外还检出较复杂的3-乙烯基-1,2-二硫代杂环己-5-烯类物质.低温条件下,茎中石油醚...     

Pyrethroid soil extraction,properties of mixed solvents and time profiles using GC/MS-NICI analysis

Ultrasonic extraction was used to develop a suitable binary solvent system for the analysis of synthetic pyrethroid pesticides and mirex on soil. The analysis was carried out by gas chromatography with negative ion chemical ionization mass spectrometry (GC/MS-NICI). In the initial experiments, accurately weighed soil samples were spiked with a mixture of standard solution pyrethroids and mirex and shaken for 24?h to ensure homogeneity, then extracted with solvent. The extracts were evaporated to dryness before the volumetric internal standard was added.

The binary solvents used in this study were various mixtures of hexane?:?acetone, hexane?:?dichloromethane (DCM), isooctane?:?acetone and isooctane?:?dichloromethane, representing different classes of polarity. The recoveries of all pyrethroids and mirex were satisfactory over three solvent systems: hexane?:?acetone, hexane?:?DCM and isooctane?:?acetone, but results of isooctane?:?DCM produced low recoveries. The average recovery increased with the extraction time, but the increase was not statistically significant. A 30-min optimum extraction was deemed sufficient for recovering pyrethroids from soil. After 30?min, extraction decreased owing to the re-distribution of the analyte on the soil matrix.     

烟草制品中紫苏葶的气相色谱/质谱法分析

以二氯甲烷为溶剂,丙酸苯乙酯为内标,将烟草制品进行萃取,经固相萃取柱纯化,采用气相色谱／质谱法定量分析了烟草制品中的紫苏葶．方法的定性检测限为0．11μ/g,定量检测限为0．36μ/g,平均回收率为95．53％,相对标准偏差（RSD）为1．89％．     

The determination of polychlorinated biphenyl in small samples of monkey milk and tissues. II. Extraction efficiency

The extraction efficiency of benzene, toluene, dichloromethane, acetone:hexane and chloroform:methanol with respect to lipids and polychlorinated biphenyls was investigated using small samples of monkey adipose tissue, liver, kidney, brain, skin, feces and milk. The most efficient solvents were: acetone:hexane and chloroform:methanol for brain, feces, kidney, liver and milk; acetone:hexane and dichloromethane for adipose tissue; acetone:hexane and toluene for blood and dichloromethane for skin tissue. Within these solvent pairs acetone:hexane was the most outstanding with respect to an average of 90% PCB recoveries from fortified samples in the range of 0.02-2 ppm. In addition, a comparison was made between the lipid determination before and after Florisil column chromatography. Only adipose and blood lipids were sufficiently recovered from Florisil to make a lipid determination after chromatography feasible.     

加速溶剂萃取-气相色谱-质谱法测定固体废物中酚类化合物

提出了气相色谱-质谱法测定固体废物中12种酚类化合物残留量的方法。样品以丙酮-二氯甲烷(2+3)混合液为萃取剂,经加速溶剂萃取仪提取后,在K-D浓缩装置上浓缩至1 mL,经硅胶柱净化后,用丙酮-二氯甲烷(1+9)混合液淋洗后再经K-D浓缩至1 mL,通过HP-5 MS石英毛细管色谱柱(30 m×0.25 mm,0.25μm)分离,采用电子轰击离子源选择离子监测模式进行质谱测定。12种酚类化合物的检出限(3S/N)在9.60～18.5μg.kg-1之间。以空白土壤样品为基体进行回收试验,测得回收率在74.7%～108.4%之间,测定值的相对标准偏差(n=7)均小于7.5%。     

Improved Method for the Determination of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/Fs) in Sanitary Napkins

Abstract

An improved method was developed for determining highly toxic 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-p-furans (PCDD/Fs) in sanitary napkins. Samples were extracted by Soxhlet (50% dichloromethane/hexane) and sonication (hexane), and a multi-layer silica column was used for clean-up after acetone precipitation to separate the superabsorbent polymers. Improved separation efficiency of PCDD/Fs from sanitary napkins with a high level of superabsorbent polymers was achieved using the acetone precipitation method. Hexane was then applied as an alternative solvent to remove residual interfering substances including sticky components contained on sanitary napkins via alumina column chromatography in the second clean-up step. Recoveries approached 100% with an average relative standard deviation of less than 15%, and recoveries of internal standards were from 70.5 to 114.8% and 0.6 to 13.6% for the two extraction methods. The mean method detection limit was 0.075–0.968?pg/g for Soxhlet extraction and 0.0032–0.091?pg/g for sonication extraction. The established method meets the quality criteria for the screening of dioxins stated in EU Regulations 589/2014 and 709/2014, and therefore provides a suitable alternative for the determination of dioxins in sanitary napkins containing superabsorbent polymers.     

Comparison of Different Extraction Techniques of Polychlorinated Biphenyls from Sediments Samples

In this work, problems that may occur during determination of trace levels of polychlorinated biphenyls in sediment samples are described. Main error sources are connected with extraction of analytes prior to final determination.

During model studies, polychlorinated biphenyls have been extracted from sediment reference material (METRANAL 2) with the use of different solvents (dichloromethane, hexsane, and toluene); the process has been enhanced by mechanical shaking or ultrasounds. Seven selected PCBs (PCB 28, 52, 101, 118, 138, 153, and 180 – according to IUPAC) were determined in extracts samples by GC–MS technique.

During the studies, two calculation methods were applied to determine the amount of analytes introduced to the chromatographic column. The first approach assumes that the recovery of PCBs that contained a small amount of chlorine atoms in the molecule is similar to the recovery of ¹³C₁₂PCB28 standard, whereas compounds with greater number of chlorine atoms in the molecule will be recovered from the sediment similarly to the recovery of ¹³C₁₂PCB180 standard. The second approach assumes that the recovery of PCB 138 and PCB 153 is similar to the average value of ¹³C₁₂PCB28 and ¹³C₁₂PCB180 standards.

In the case of shaking assisted extraction, 55–90% PCB recoveries were achieved when toluene was used as a solvent, while 71–86% recovery was achieved when dichloromethane was used. When hexsane was used as solvent, recovery ranged 43–107%. In the case of ultrasounds assisted extraction, PCB recoveries of 50–108% were achieved when toluene was used as solvent, while 44–101% recovery was achieved when dichloromethane was applied. When hexsane was used as solvent, recovery reached 57–95%.

Studies have also shown that, when applying different isolation techniques and different solvents, the recovery of applied ¹³C₁₂PCB28 and ¹³C₁₂PCB180 standards is different. Recovery of ¹³C₁₂PCB28 standard was from 5% (for hexane tenfold extraction assisted by shaking) to 57% (for toluene tenfold extraction assisted by shaking). However, recovery of ¹³C₁₂PCB180 standard was from 9% (for hexane tenfold extraction assisted by shaking) to 82% (for toluene tenfold extraction assisted by shaking). This is due to the differences of their binding to the sludge matrix. Standard with a greater number of chlorine atoms in the molecule (¹³C₁₂PCB180) is more weakly associated with sediment than ¹³C₁₂PCB28 standard. In order to improve the accuracy of the results obtained, it is necessary to use labeled PCB compounds.     

Statistical mixture design investigation of fractionated and total extracts from Erythrina speciosa Andrews leaves

The simplex centroid mixture design for the ethanol, dichloromethane, hexane and acetone solvents has been applied to the extraction of crude mass and the fiber, organic, neutral and basic fractions as well as the fractionation residues of Erythrina speciosa Andrews leaves. Binary and ternary synergic solvent interactions are seen to provide dominant contributions to the extraction of both crude mass and all the fractions. Quadratic and special cubic mixture models precisely predict the extracted quantities of each fraction and the residue as a function of the proportions of the four solvents. Different solvent mixtures are found to be the most efficient extractors for the different fractions: binary dichloromethane‐hexane mixtures for the fiber fraction, ternary ethanol‐dichloromethane‐acetone mixtures for the neutral fraction, binary ethanol‐dichloromethane mixtures for the organic fraction, crude extract and residue values and ternary ethanol‐dichloromethane‐hexane mixtures for the basic fraction. Principal component analysis shows that the ethanol‐dichloromethane mixtures are important for extracting large quantities of the basic and organic fractions as well as of the residue and crude masses.     

Comparison of solvent extraction and solid-phase extraction for the determination of organochlorine pesticide residues in water.

Solid-phase extraction (SPE) of organochlorine pesticide residues from environmental water samples was evaluated using octadecyl (C18)-bonded porous silica. The efficiency of SPE of these pesticide residues from reagent water samples at 1-5 micrograms dm-3 levels was compared with those obtained by solvent extraction with hexane and Freon TF (trichlorotrifluoroethane). Average recoveries exceeding 80% for these organochlorine pesticides were obtained via the SPE method using small cartridges containing 100 mg of 40 microns C18-bonded porous silica. The average recovery by solvent extraction with hexane and Freon TF exceeded 90% in both instances. It was concluded that the recoveries and precision for the SPE of organochlorine pesticides were poorer than those for the solvent extraction method. Organochlorine pesticide residue levels in environmental water samples from two major rivers flowing through predominantly rice-growing areas were monitored by gas chromatography using the solvent extraction method with hexane. Exceptionally high levels of organochlorine pesticide residues such as BHC, DDT, heptachlor, endosulfan and dieldrin were found in these water samples.