Development of Different Strategies for the Clean-Up of Polychlorinated Biphenyls (PCBs) Congeners Using Pressurized Liquid Extraction

The extracted fish samples (w/w) using pressurized liquid extraction (PLE) were cleaned up by applying different adsorbent materials such as: combination of acidic/ basic silica and alumina, florisil, and silica gel either alone or in combination with another sort of sorbent. Different solvents such as hexane (H), dichloromethane (DCM), with different compositions were used to elute the PCBs target compounds from the spiked fish samples. Overall the mean percentage recoveries for all PCBs congeners using PLE were ranging from 78.6% to 98.7%;from 79.4% to 91.8%;from 65.8% to 104.5% and from 82.4% to 100.9% for cases A, B, C, D and E, respectively. However, the overall mean percentage recoveries for the 13C-PCBs surrogate including: 101, 138, 153, 180 and 209 were ranging from 88.2% to 97.6%;from 79.4% to 90.2%, from 88.3% to 96.4%, from 79.8% to 90.4% and from 83.9% to 95.9%, for cases A, B, C, D and E, respectively. The limits of detection of the proposed method were varied from 0.01 to 0.28 ng/g (w/w) for different PCBs congeners. The proposed method has linear dynamic range from 21.5 ng/g to 109 ng/g. This method was applied to fish samples for the determination of the target PCBs components.

Isolation and purification of carbazole contained in anthracene slag by extraction combined with medium pressure liquid chromatography

Ultrasonic-assisted extraction(UAE)combined with medium pressure liquid chromatography(MPLC)was designed for carbazole separation from anthracene slag(AS).The effects of liquid/solid ratio,temperature,and extraction times on carbazole separation were investigated.When using CC14 and ethyl acetate as extraction solvents and combining with MPLC,carbazole recovery and purity are 75.1%and 95.4%,respectively.The mechanism for carbazole separation were presumed by examining intermolecular interactions such as N-H…π,π-π,and C-Cl…πinteractions.These results demonstrate that UAE/MPLC has a considerable potential as a green and promising strategy for separating and purifying carbazole and other chemicals from AS.

Determination of 16 Species of OCPs in Water by Liquid-liquid Extraction-GC

[Objective] The research aimed to study the determination of 16 kinds of OCPs in water by liquid-liquid extraction -GC. [Method] The new method for determining 16 kinds of OCPs in water by liquid-liquid extraction -GC was established, and the influencing factors such as nitrogen pressure and water bath temperature were discussed. [ Result] Detection limit of the method was from 3.2 to 14.1 ng/L, the relative standard deviation was between 4.0% and 9.6%, and the average recovery ranged from 80.8% to 106.0%. By optimizing nitrogen pressure and water bath temperature in the sample pretreatment process, when nitrogen pressure was ＋0.087 kPa, and water bath temperature was ±36 ℃, recovery effect of this method was better. [ Conclusion] The determination method had accurate qualitative and quantitative results, and met detection requirement of 16 kinds of OCPs in water.

糠醛精制装置工艺优化降低抽出油溶剂含量

糠醛精制装置受糠醛结焦温度所限,抽出油回收系统经三效蒸发后,汽提塔底温度难以进一步提高。在加工高芳烃原料时,因溶剂对芳烃溶解性好,产品抽出油溶剂含量高。采用抽出液二次加热的方法可以提高抽出油汽提塔底温度,对降低抽出油溶剂含量效果较好。通过模拟计算得出安装抽出液二次加热器的最优位置,推荐设置在三效蒸发塔与闪蒸塔之间,相比无二次加热可以降低抽出油溶剂含量约83.1%。计算得出汽提塔最优汽提蒸汽用量为塔底抽出油量的5%,汽提塔顶温度和汽提塔底抽出油溶剂含量近似成反比关系,但汽提塔顶温度的提高需要注意塔顶气中携带油的影响。小负荷运行或者设计加工量较小的装置,通过设置抽出油循环流程,可提高汽提塔底温度,有利于降低汽提塔底溶剂含量。通过设置抽出油二次加热、抽出油循环流程,优化汽提塔操作压力、塔顶温度、汽提蒸汽量等,实际运行可以将抽出油溶剂质量分数控制在小于150μg/g,降低了装置溶剂消耗。

PLE萃取-GPC净化-LC-MS/MS法测定沉积物中8种性激素

建立了加压液体萃取(PLE)-凝胶渗透色谱(GPC)净化-液相色谱-串联质谱法(LC-MS/MS)测定沉积物中8种性激素含量的方法。结果表明,8种性激素在10~1 000μg/L范围内呈良好的线性关系,相关系数R^2≥0.999 6;检出限在10~100μg/kg之间;加标回收率为85.6%~101.4%,RSD为0.8%~2.7%。该方法自动化程度高,灵敏度高,回收率好。

加压液体提取-自动SPE-UPLC-MS/MS法检测农业土壤中6种吡啶类农药微量残留

以农业土壤为研究对象,建立采用加压液体提取法将样品中啶氧菌酯、氟啶草酮、吡虫啉、啶酰菌胺、氟啶酰菌胺、啶虫脒6种吡啶类农药提取出来,全自动固相萃取法富集、净化,超高效液相色谱-质谱联用仪定量检测的分析方法。取农业土壤样品,风干、粉碎后,过120目筛,准确称取过筛网后的样品10 g,置萃取池中,加硅藻土20 g,用甲醇:丙酮溶剂(V∶V=1∶1)提取,另取规格为500 mg/12 mL HLB固相萃取小柱,置全自动固相萃取仪中,活化完毕后,设定程序,将上述提取液以20 mL/min的流量,过固相萃取柱,最后用20 mL甲醇-乙腈(V∶V=1∶1)洗脱,收集洗脱液,洗脱液氮吹至近干,加甲醇定容至1 mL,涡旋混匀,上液相色谱-质谱仪定性、定量检测。啶氧菌酯、氟啶草酮、吡虫啉、啶酰菌胺、氟啶酰菌胺、啶虫脒6种吡啶类农药在0.001~5.0μg/mL范围内具有良好的线性,相关系数均大于0.995;检测限分别为0.012、0.009、0.024、0.007、0.013、0.005μg/L。三水平加标回收率均在84.4%~105.2%之间;重复性RSD(n=6)分别为2.0%、3.1%、2.3%、2.2%、1.9%和2.3%。实验结果表明,实验建立的方法具有准确、灵敏等优点,适用于农业土壤中微量吡啶类农药残留的检测。

基于UPLC-MS/MS的土壤中敌草隆残留检测技术

为了提高土壤中敌草隆的萃取效率,更为精确地检测其残留量,采用加压溶剂萃取作为土壤中敌草隆的萃取方式,使用超高效液相色谱-三重四极杆串联质谱法对土壤中残留的敌草隆进行了检测,建立了一种土壤中敌草隆萃取和检测的新方法。试样经冷冻干燥处理后,将其研磨样装入加压溶剂萃取仪,使用2∶1的甲醇-二氯甲烷混合溶液作为萃取剂,萃取液经Carb/PSA石墨化炭黑/乙二胺-N-丙基固相萃取柱净化后,通过C18色谱柱进行分离,并以体积比为1∶9的甲醇-二氯甲烷混合溶剂进行梯度洗脱,质谱中选择电子轰击离子源和多反应监测模式。结果显示,敌草隆在20~500μg·L^(-1)范围内具有良好的线性关系,相关系数为0.999 5,且目标峰分离效果较好;不同浓度下敌草隆的加标回收率为71.2%~90.3%,相对标准偏差为1.7%~9.4%,检出限为0.000 287μg·g^(-1)。该方法有利于对土壤中敌草隆残留量大批量检测的操作,提高了目标物的萃取效率和检测效率,提高样品检测准确性。

Comparison of Accelerated Solvent Extraction, Soxhlet and Sonication Techniques for the Extraction of Estrogens, Androgens and Progestogens from Soils

Leaching of hormones from manure amended fields to receive surface water can lead to endocrine disruption in resident fish populations. In order to determine the concentrations of hormones present in manure amended soils, and thus the potential for soils to release hormones to aquatic environments, efficient extraction methods are needed. In this study, the efficacy of three techniques (accelerated solvent extraction [ASE], Soxhlet and sonication) for the extraction of estrogens, androgens and progestogens, as well as their metabolites, from various soil types were evaluated. The stability of hormones spiked into these soils and stored for 30, 90 and 210 days at -20°C was also investigated. Four experimental soil matrices (reagent sand, silt loam, clay and high organic) were spiked with 50 μL of 10 μg·mL-1 (in methanol;final conc. 100 ng·g-1) of a stock mix of hormones and isotopically-labeled standards (ISTDs). After equilibration, triplicate samples of the spiked soils were extracted by ASE, Soxhlet and sonication techniques and analysed, without post extraction cleanup, using HPLC-MS/MS. Sonication and ASE were effective at extracting hormones from all matrices with overall average apparent recoveries, for all 19 extracted analytes, of 71% ± 23% and 73% ± 16%, respectively. Soxhlet was significantly less efficient (p < 0.05) with overall average apparent recoveries of 58% ± 34%. Incorporation of ISTDs resulted in overall average process efficiencies of 108% ± 24%, 102% ± 24% and 180% ± 310% for ASE, Soxhlet and sonication, respectively. The hormones had variable stability in soils stored for at least 30 days, and therefore it recommended that soil samples be analysed within 30 days of sampling.

离子液体萃取剂萃取精馏分离丙酸甲酯+甲醇共沸物

以离子液体(ILs)[BMIM][NTF_(2)]和[HMIM][NTF_(2)]为萃取剂,萃取精馏分离丙酸甲酯+甲醇共沸物,通过分子模拟分析了ILs促进目标共沸物的分离机理;基于汽液平衡实验数据,获得新的NRTL热力学模型参数;选用常规的二组分双塔分离流程,实现了目标共沸体系的分离。作为对比,同时构建了以苯酚为萃取剂的萃取精馏和变压精馏流程。基于Aspen Plus软件平台,分析了上述各流程分离单元主要操作参数对分离过程性能的影响,考察并对比了各流程能耗、年总成本(TAC)和碳排放。结果表明:离子液体工艺可实现丙酸甲酯+甲醇共沸物的有效分离,产品纯度达到99.9%(质量分数),[HMIM][NTF_(2)]工艺与[BMIM][NTF_(2)]、苯酚及变压精馏工艺相比,TAC降低11.68%~43.68%、CO_(2)排放减少32.11%~68.46%。结果可为共沸物丙酸甲酯+甲醇分离新工艺设计及优化提供理论支撑和实际指导。

Pressurized Liquid Extraction of Pigments from Chlamydomonas sp.and Chemical Characterization by HPLC–MS/MS

Pressurized liquid extraction using green solvents(ethanol and water)was applied to extract photosynthetic pigments from the microalgae Chlamydomonas sp.An experimental design is employed to determine the effect of the extraction conditions on the extraction yield and the antioxidant capacity of the different extracts determined using 1,1-diphenyl-2-picryl-hydrazyl and TEAC tests.All the extracts show significant antioxidant activity in all assays.Besides,in this work,the carotenoid and chlorophyll composition of the Chlamydomonas extracts was analyzed by HPLC–DAD–APCI–MS/MS for the first time,being the main compounds lutein and pheophythin a′.

土壤中双酚A测定时不同前处理方法比较分析

目的:针对土壤中双酚A的测定,通过横向比较分析索氏提取法、快速溶剂萃取法、超声波提取法、微波提取法等4种萃取方法的各自优缺点,选择更加适合的前处理方法。方法:建立了土壤中双酚A的气相色谱质谱分析方法,样品分别用4种前处理方法进行提取、净化和浓缩,通过MS检测双酚A的浓度。结果:经试验分析,索氏提取法、快速溶剂萃取法、微波提取法和超声波提取的加标回收率分别为83.7%~92.0%、81.3%~90.2%、81.3%~89.7%和70.3%~81.7%,其中超声波提取法的萃取效率较低,其余3种方法无显著性差异。结论:快速溶剂萃取法、微波提取法具备萃取效率高,溶剂用量少,萃取时间短,自动化程度高,工作效率快等特点,更适用于土壤批量化分析。

加压溶剂萃取-气相色谱法测定荞麦中残留的有机氯农药

用所研制的24位全自动加压溶剂萃取仪（APLE），以丙酮-正己烷（体积比为1：1）为溶剂，在100℃和10MPa条件下，对荞麦样品中残留的7种有机氯农药进行了萃取，并通过气相色谱对萃取液进行定量分析。萃取的绝对回收率为68％～126％．相对标准偏差为1．2％～14．7％，检测下限为0．051～0．18ng／g。与索氏提取法对比，相对提取回收率为116％～148％，表明萃取收率高于索氏提取法。

超高压提取丹参素的研究

该文研究常温下超高压提取丹参素的最优工艺。采用超高压常温提取,正交试验对丹参素超高压提取工艺优化,高效液相色谱法测定丹参素的含量,并与传统的热回流提取法进行比较。结果显示优选的最优工艺为:提取压力300 MPa,溶剂乙醇浓度80%,溶液pH 13,浸泡时间16 h,在此条件下丹参素得率为0.465%。超高压提取不仅得率高、时间短、耗能低,而且提取产物易于分离、纯化,同时超高压提取可以维持在低温下进行,特别适宜于受热不稳定化合物的提取,该技术适合中药有效成分的快速提取。

基质固相分散-加压溶剂萃取法测定土壤中多环芳烃

建立基质固相分散(MSPD)辅助加压溶剂萃取(PLE)-高效液相色谱法测定土壤中16种多环芳烃的方法.土壤样品与弗罗里硅土混匀后装入萃取池,在15 MPa、120℃萃取条件下,丙酮∶二氯甲烷(1∶1,V∶V)作为萃取溶剂,静态提取5min,应用高效液相色谱法荧光检测-二极管阵列检测串联,采用外标法对其进行定量分析.结果表明:16种多环芳烃线性关系良好,相关系数均大于0.9994,利用荧光检测器与二极管阵列检测器的方法检出限分别为0.04—0.8μg·L-1、0.6—20μg·L-1,在低、中、高3个水平下的加标回收率在78.4%—105.8%范围内,测定结果的相对标准偏差为1.2%—4.1%(n=5).

加压溶剂提取高效液相色谱法测定天然和人工虫草中的麦角甾醇、核苷及其碱基

目的 建立同时测定虫草中麦角甾醇、核苷及其碱基含量的简便方法。方法 正交法优化加压溶剂提取条件 ;HPLC法同时测定天然和人工虫草中上述成分的含量。结果 以甲醇为提取溶剂 ,提取温度 16 0℃ ,提取时间 5min ,提取压力 10MPa ,循环 1次 ,提取 1次。采用ZorbaxNH2 分析柱 (2 5 0mm× 4 6mmID ,5 μm) ,流动相为A(乙腈 ) B(10mmol·L- 1 醋酸铵溶液 )二元梯度洗脱 :0 - 5 0min ,B %为 0→ 15 % ;5 0 - 2 5 0min ,B %为 15 %→ 2 0 % ;2 5 0 - 35 0min ,B %为 2 0 %→ 4 0 % ;35 0 - 4 5 0min ,B %为 4 0 %→ 80 % ;4 5 0 - 5 0 0min ,B %为 80 %。结论 本法能够快速、简便地测定虫草中麦角甾醇、核苷及其碱基的含量。

甲醇-丙酮共沸物分离的研究进展

主要介绍了甲醇-丙酮共沸物系变压精馏和萃取精馏两种分离方法的研究进展。经过比较,萃取精馏方法在经济成本方面更具有显著优势。关于萃取精馏,首先阐述了萃取剂的选取以及近些年来萃取剂的研究,主要集中在3个方面:传统单一溶剂、各种盐类和离子液体。其次还介绍了各种萃取剂所对应的气液平衡模型的应用情况和操作条件的优化等方面,并对萃取精馏及其萃取剂的应用提出了展望。

固相萃取/超高压液相色谱测定水中痕量呋喃丹、甲萘威及阿特拉津

建立了固相萃取/超高压液相色谱测定水中痕量呋喃丹、甲萘威和阿特拉津的分析方法。通过对色谱流动相和紫外检测条件、固萃小柱和上样速度、滤器材质等进行优化,确定了最佳实验方案。水样以5～10 mL/min的速度上样,采用Bond Elute Plexa固相萃取小柱富集,二氯甲烷洗脱。洗脱液经浓缩和重溶后,过尼龙滤膜,采用超高压液相色谱分析,色谱柱为ACQUITY UPLC BEH C18(2.1 mm×50 mm,1.7μm),流动相为甲醇-水(55∶45),检测波长为222 nm,流速为0.4 mL/min。在优化条件下,1.5 min内可对3种化合物实现基线分离。呋喃丹、甲萘威和阿特拉津在0.1～2.0 mg/L范围内的线性系数均大于0.999,其仪器精密度(n=9)分别为1.7%、0.2%和0.7%,方法检出限(S/N=3)分别为0.04、0.003、0.004μg/L。在高、低水平加标浓度下,方法回收率为74%～94%。该方法具有分析速度快、操作简单和检出限低等优点,可用于同时分析水体中痕量的呋喃丹、甲萘威和阿特拉津。

RP-HPLC法测定鹅膏菌中毒患者体液中的α-amanitin

建立了反相高效液相色谱法检测蘑菇中毒患者体液中的αamanitin及其含量的方法,使用填料为YEGC18,10μm的反相柱,10%的乙腈+90%0.02mol/L的醋酸铵和24%的乙腈+76%0.02mol/L的醋酸铵为流动相,冰醋酸pH5.0,检测波长295nm,流速为1mL/min,柱温40℃,样品用无水甲醇提取;结果表明αamanitin进样在0.01～0.1μg的范围内与峰面积呈良好线性关系,相关系数r为0.9958,回收率为97.9%.

加速溶剂萃取-高效液相色谱串联质谱法测定土壤中邻苯二甲酸酯

建立了高效液相色谱串联质谱技术（Liquid chromatography tandem mass spectrometry,LC-MS/MS）同时测定土壤中邻苯二甲酸酯（Phthalic acid esters,PAEs）的分析方法。确定了土壤样品加速溶剂萃取最优条件是以正己烷为萃取溶剂,在160℃下,静态萃取4次,每次12 min,萃取液经旋转蒸发浓缩,以乙腈-0.1%甲酸溶液为流动相梯度洗脱分离后,用LC-MS/MS结合大气压化学源（Atmospheric pressure chemical ionization,APCI）进行定性及定量分析。土壤中11种PAEs的浓度与其峰面积呈良好的线性关系,检出限为0.03-13.0μg/kg,样品的加标平均回收率为72.8%-101.8%,相对标准偏差（RSD）为1.7%-6.7%。方法简便快速,且灵敏度高,适用于土壤中11种邻苯二甲酸酯的同时测定。