应用搅拌棒吸附萃取-热脱附-气质联用技术分析人工唾液捕集吸收的卷烟主流烟气成分

采用人工唾液捕集卷烟主流烟气,应用搅拌棒吸附萃取法(SBSE)提取其中的化学成分,利用热脱附(TD)-气相色谱-质谱(GC-MS)进行分析。对脱附温度、脱附时间、冷阱温度、萃取时间及NaCl加入量等影响因素进行考察,获得优化的实验条件。在优化条件下,同一样品的6次测定所得44个组分的峰面积的相对标准偏差(RSD)平均值小于10%,说明所建方法重现性较好。应用本方法分析某品牌卷烟烟气成分的结果表明:SBSE-TD-GC-MS联用技术可用于人工唾液捕集吸收的烟气化学成分的快速分析测定。     

应用搅拌棒吸附萃取-热脱附-气相色谱-质谱测定烟叶和茶叶中拟除虫菊酯类农药残留

应用搅拌棒吸附萃取(SBSE)技术分别萃取烟叶和茶叶中的5种拟除虫菊酯,并利用热脱附系统将萃取到的物质进行热脱附,然后通过气相色谱-质谱联用仪(GC-MS)进行分析测定。实验过程中对影响SBSE的因素及影响热脱附的条件进行了优化。在优化条件下,采用外标法分别对烟叶和茶叶中的5种拟除虫菊酯类农药残留进行了定量分析。结果表明,烟叶中5种拟除虫菊酯的检出限范围为3.3~11.4 ng,加标回收率为94.8%~103.4%,6次测定的相对标准偏差（RSD）为5.3%~8.6%;茶叶中5种拟除虫菊酯的检出限范围为4.2~10.5 ng,加标回收率为98.2%~110.1%,6次测定的RSD为5.0%~9.6%。实验证明该法具有较高的准确度、灵敏度和较好的重现性,可用于烟叶和茶叶中拟除虫菊酯类农药残留的快速分析测定。     

固相萃取搅拌棒萃取-气相色谱分析海水中的多环芳烃

利用固相萃取搅拌棒（SBSE）萃取海水中的多环芳烃，然后用热解吸脱附-气相色谱分析。研究了萃取时间、添加NaCl浓度对萃取效率的影响。实验结果表明，SBSE方法对16种多环芳烃的萃取回收率分别在33．5％～122．4％之间；对标准样品的检出限为2．74-13．5ng／L；方法RSD为3．8％～13．1％。用此方法测定了大连海岸海水中的多环芳烃含量。     

闪蒸-气相色谱指纹图谱及系统聚类分析用于烟用香精香料的测定

采用闪蒸-气相色谱法(FE-GC)对不同黏度的烟用香精香料样品进行测定,考察了影响测定的主要因素。结果表明,0.40 mg样品在350 ℃下进行FE-GC分析,可以得到重现性良好的色谱图。与超声辅助液-液萃取-气相色谱法(ULLE-GC)分析结果的比较表明,FE-GC适用于不同黏度样品的分析。采用该法检测了中等黏度的烟用香精香料1184号8个批次样品,并建立其指纹图谱。利用系统聚类分析法可以明显区分1184号样品及掺兑10%～30%其他种类烟用香精香料的样品。FE-GC法简便、快速、灵敏,适用于不同黏度的烟用香精香料样品的检测和质量控制分析。     

聚酰亚胺固相萃取搅拌棒的制备及其在环境水中酚类的分析应用

利用相转换法制备了聚酰亚胺吸附萃取搅拌棒,用5种有机酚作为评价标样,并与现有商品化吸附萃取搅拌棒进行比较。优化了萃取搅拌速度、溶液离子强度、萃取温度、萃取时间以及热解析温度和时间。在最佳实验条件下,100 mL 样品,30% NaCl,在25℃下,经活化5 min 后的聚酰亚胺吸附搅拌棒萃取30 min (800 r/ min),然后300℃热解析4 min,使目标物脱附,再进行色谱分析。目标物在大于两个数量级浓度范围内具有良好的线性(R≥0.9995),定量限(LOQ,S/ N=10)为0.028~0.123μg/ L,重复性为1.6%~9.7%。将SBSE 与气相色谱-质谱联用,对海水、自来水和污水中的酚类进行定性与定量分析,结果表明,聚酰亚胺吸附萃取搅拌棒具有良好的选择性,最高热解析温度350℃,在分析水中痕量极性化合物领域具有广阔应用前景。     

顶空固相微萃取-气相色谱-质谱联用分析干柴胡药材中有机挥发物

采用顶空固相微萃取与气相色谱-质谱联用技术检测分析干柴胡药材中挥发性成分,选用聚丙烯酸酯涂层,就萃取时间、温度、体积、样品量、预热时间及脱附时间等条件进行了优化,结果表明,30mL萃取瓶里0．5g样品90℃温度下预热40min后,以85μmPA涂层顶空萃取50min,于250℃脱附5min,测得88个峰,鉴定26种化合物成分。方法所得结果与传统提取方法(蒸馏提取法)比较,相对含量较高的成分一致,方法重现性理想,可应用于柴胡药材挥发性物质的快速分析。     

在线固相微萃取在烟用料液的指纹图谱中的应用

为解决现有烟用料液指纹图谱的信息量少、水溶性成分反映不充分、特征反映不明显的问题,本文建立了烟用料液在线固相微萃取-气相色谱指纹图谱分析方法。运用正交实验设计,比较萃取头、萃取时间、萃取温度、脱附时间、NaCl的加入量这五个因素对固相微萃取结果的影响。引用信息量和峰面积作为判别准则,确定固相微萃取的最佳条件。比较在线固相微萃取方法与乙醚液-液萃取方法,结果表明固相微萃取方法用于测定烟用料液的指纹图谱具有较高的信息量和较好的重现性。采用在线固相微萃取结合气相色谱-质谱(GC-MS)分析烟用料液结果进行定性分析,共鉴定出34种组分,其主要成分为丙二酸二乙酯、胡椒醛、对甲氧基苯乙酮、香兰素、茄酮等。     

搅拌棒萃取-热解吸气相色谱法测定水中倍半芥子气

建立了一种以SBSE萃取与热解吸-气相色谱-火焰光度法联用技术为基础的测定水中倍半芥子气的方法。对比了SBSE和固相微萃取(SPME)对水中的倍半芥子气的萃取回收率,实验结果表明,SBSE对倍半芥子气的萃取率在22.47%～22.60%之间,SPME对倍半芥子气的萃取率为0.4%。研究了萃取时间、解吸附时间、样品溶液pH值、萃取温度对萃取回收率的影响,选择萃取时间为20min、一级解吸时间为10min、二级解吸时间为4min、样品溶液pH值为7.0、萃取温度为25℃。检测倍半芥子气的线性范围为0.462～23.1μg/L,最低检出限为0.0924μg/L(S/N=3)。该方法已成功应用于河水的检测。     

热脱附-气相色谱-质谱法同时测定工作场所空气中10种醇类和醚类化合物的含量北大核心CSCD

通过对比填充不同吸附剂的不锈钢吸附管对10种醇类和醚类化合物的吸附能力,优化热脱附条件,考察不同色谱柱和样品保存时间对测定结果的影响,提出了热脱附-气相色谱-质谱法同时测定工作场所空气中10种醇类和醚类化合物含量的方法。用填装Tenax GR的吸附管采集气体样品,采集完成后将吸附管两端封好,设置一次热脱附温度为220℃,二次热脱附温度为240℃,吹扫时间为4 min,进样时间为50 s,在上述条件下进行热脱附,脱附的气体进入气相色谱仪,采用DB-624毛细管色谱柱分离目标物,并用配电子轰击离子源的质谱仪在选择离子监测模式下检测。结果显示:10种醇类和醚类化合物的质量在10~300 ng内与其对应的峰面积呈线性关系,检出限(3.143s)为0.5~1.9 ng;对空白样品进行3个浓度水平的加标回收试验,回收率为70.5%~125%,测定值的相对标准偏差(n=6)为1.0%~20%;方法用于实际样品分析,正丁醇、异丁醇和仲丁醇被检出,检出量依次为0.013,0.007,0.008 mg·m^(-3)。     

顶空液液萃取-气相色谱-质谱法用于白术挥发性成分的分析

采用高温顶空液相萃取再转移的方法,对中药白术中挥发性成分进行萃取分离富集,采用顶空液液萃取/气相色谱-质谱(HS-LP-LPE/GC-MS)联用法进行测定,并与传统水蒸汽蒸馏法(SD)提取的挥发性成分进行对比。对各种测定条件和影响因素进行了考察,最佳萃取条件为:1.0 mL PEG 400为高温萃取剂,样品用量1.2 g,萃取温度120℃,萃取时间60 min,再将萃取剂用1.0 mL正己烷进行反萃取后进行GC-MS分析;采用HS-LP-LPE/GC-MS鉴定了33个组分,占总组分含量93.18%;SD鉴定了31个组分,占总组分含量97.12%。两种方法共同检测到的组分有29个,均以苍术酮(Atractylone)含量最高。结果表明,两种方法所提取的组分基本相同,可用于白术挥发性成分的测定。     

Analysis of 35 priority semivolatile compounds in water by stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry. I. Method optimisation

A multiresidue method for the determination of 35 organic micropollutants (pesticides and polycyclic aromatic hydrocarbons) in water has been optimised using stir bar sorptive extraction (SBSE) and thermal desorption coupled to capillary gas chromatography-mass spectrometry (GC-MS). In the present work, the different parameters affecting the extraction of the analytes from the water samples to the PDMS-coated stir bars and optimisation of conditions affecting thermal desorption are investigated. The optimised conditions consist of a 100-ml water sample with 20% NaCl addition extracted with 20 mm length x 0.5 mm film thickness stir bars at 900 rpm during 14 h at ambient temperature. Desorption is carried out at 280 degrees C during 6 min under a helium flow of 75 ml/min in the splitless mode while maintaining a cryofocusing temperature of 20 degrees C in the programmed-temperature vaporisation (PTV) injector of the GC-MS system. Finally, the PTV injector is ramped to a temperature of 280 degrees C and the analytes are separated in the GC and detected by MS using full scan mode (m/z 60-400). Under the described conditions, the good repeatability, high analyte recoveries and robustness, make SBSE a powerful tool for routine quality control analysis of the selected semivolatile compounds in water samples.     

Stir bar sorptive extraction and trace analysis of alkylphenols in water samples by thermal desorption with in tube silylation and gas chromatography-mass spectrometry

A novel method called thermal desorption (TD) with in tube silylation followed by gas chromatography-mass spectrometry (GC-MS), which is used for the determination of trace amounts of alkylphenols (APs) in river water samples, is described. APs are extracted from river water samples and concentrated by the stir bar sorptive extraction (SBSE) technique. The stir bar coated with polydimethylsiloxane (PDMS) is added to 2.0 ml water sample and stirring is carried out for 60 min at room temperature (25 degrees C) in the vial. Then, the PDMS stir bar is subjected to TD with in tube silylation followed by GC-MS. The detection limit is of the sub pg ml(-1) (ppt) level. The method shows good linearity and the correlation coefficients are higher than 0.99 for all analytes. The average recoveries of APs are higher than 90% (R.S.D.: 3.6-14.8%, n=6). This simple and sensitive analytical method may be used in the determination of trace amounts of APs in river water samples.     

Optimisation of stir bar sorptive extraction applied to the determination of volatile compounds in vinegars

Stir bar sorptive extraction (SBSE) was evaluated for analysing volatile compounds in vinegar. The extraction and desorption analytical conditions have been optimised using a two-level factorial design expanded further to a central composite design. This chemometric tool is very appropriate in screening experiments where the aim is to investigate several possibly influential and/or interacting factors. For the extraction step, the optimum analytical conditions were: sample volume 25 ml without dilution, sampling time 120 min, NaCl content 5.85 g, and stirring speed 1250 rpm. For the desorption step, the optimised analytical conditions were: desorption temperature 300 degrees C, cryofocusing temperature -140 degrees C, flow of helium 75 ml min(-1), and desorption time 10 min. The SBSE procedure developed shows detection limits, and linear ranges adequate for analysing this type of compounds. The repeatability values obtained were lower than 10%. SBSE is a very simple, solvent-free, fast technique with better sensitivities, in general, than SPME. However, a disadvantage of this technique is that, up to now, the stir bar offers a limited enrichment capability for polar compounds because is only available with PDMS coating.     

Analysis of wine primary aroma compounds by stir bar sorptive extraction

Due to the great importance of some primary aroma compounds on wine quality, these compounds which includes terpenes, C₁₃-norisoprenoids and C₆ compounds, have been analyzed by stir bar sorptive extraction (SBSE) followed by a thermal desorption-gas chromatography-mass spectrometry analysis. The stir bar sorptive extraction method was optimized in terms of temperature, time, pH and NaCl addition. The best SBSE sorption kinetics for the target analytes were obtained after submitting the solutions to 60 °C during 90 min. The addition of sodium chloride did not enhance the volatile extraction. The method proposed showed good linearity over the concentration range tested, with correlation coefficients higher than 0.98 for all the analytes. The reproducibility and repeatability of the method was estimated between 0.22 and 9.11%. The detection and quantification limits of all analytes were lower than their respective olfactory threshold values. The application of this SBSE method revealed that monovarietal white wines were clearly separated by two canonic discriminating functions when grape varieties were used as differentiating variable, the first of which explained 98.4% of the variance. The compounds which contributed most to the differentiation were limonene, linalool, nerolidol and 1-hexanol.     

整体式吸附萃取搅拌棒在检测环境水样中镉离子含量方面的应用

通过逐步聚合反应制备了一种新型整体式吸附萃取搅拌棒,将其应用于环境水中镉离子的吸附萃取.考察了介质酸度、搅拌速率、吸咐时间、解吸溶剂和时间等实验条件对吸附量的影响.控制溶液pH为6.0,搅拌棒转速为300 r/min,吸附30 min,5% HNO3作为解吸液解吸10 min,采用等离子体原子发射光谱仪对Cd离子进行检...     

ICE Concentration Linked with Extractive Stirrer (ICECLES)

Trace and ultra-trace analysis can be difficult to achieve, especially for polar, more volatile, and/or thermally unstable analytes. A novel technique, coined ICE Concentration Linked with Extractive Stirrer (ICECLES), may help address this problem. The implementation of ICECLES described here combines stir bar sorptive extraction (SBSE) with freeze concentration (FC), where an aqueous solution is frozen during SBSE in order to concentrate analytes into a polydimethylsiloxane (PDMS) coated stir bar. Five test probe molecules with a range of log K_ows (2-butanol, benzyl alcohol, benzaldehyde, dimethyl trisulfide and bromobenzene) were prepared from aqueous solutions using ICECLES. Thermal desorption gas–chromatography mass–spectrometry was then used to quantify these analytes. Parameters affecting the performance of ICECLES (e.g., freeze rate) were evaluated, with extraction at lower speeds resulting in higher extraction efficiencies, whereas the freeze rate and initial analyte concentration only had a minor effect. ICECLES produced much higher extraction efficiencies than SBSE alone, with signal enhancements of up to 474× SBSE. ICECLES also provided excellent reproducibility and lower LODs than SBSE for all compounds tested. ICECLES performed well when used to analyze multiple triazine pesticides and breakdown products in environmental surface waters. Overall, the ICECLES technique was excellent at preparing aqueous samples for trace analysis and shows promise as a novel analytical sample preparation technology.     

Stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry for trace analysis of triclosan in water sample

A simple and highly sensitive method called stir bar sorptive extraction (SBSE) and thermal desorption (TD)-gas chromatography-mass spectrometry (GC-MS), which is used for the determination of trace amounts of 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan) in river water samples, is described. A stir bar coated with polydimethylsiloxane (PDMS) is added to a 10mL water sample and stirring is carried out for 120min at room temperature (25 degrees C) in a vial. Then, the PDMS stir bar is subjected to TD-GC-MS. The detection limit of triclosan is 5ngL(-1) (ppt). The method shows linearity over the calibration range (0.02-20mugL(-1)) and the correlation coefficient is higher than 0.997 for triclosan standard solution. The recovery of triclosan in river water samples ranges from 91.9 to 108.3% (RSD: 4.0-7.0%). This simple, accurate, sensitive, and selective analytical method may be used in the determination of trace amounts of triclosan in river water samples.