气相色谱–质谱法测定食用植物油中23种农药残留

建立了测定食用植物油中23种农药残留的气相色谱–质谱联用方法。采用固相萃取,以乙腈超声提取,经过PSA,C_(18)柱进行净化,用气相色谱–质谱法测定,外标法定量。23种农药在0.01~1.0 mg/L范围内与色谱峰面积线性关系良好,相关系数为0.997 3~0.999 7,方法检出限为5~15μg/kg。测定结果的相对标准偏差为2.25%~9.40%(n=6),加标回收率为78.4%~127.3%,可以满足食用植物油中多种农药残留的同时分析。采用该方法对国内市场常见的食用植物油进行检测分析,所检测的农药残留均在国家标准的限量范围内。     

顶空-气相色谱/质谱法测定溶剂型木器涂料中7种卤代烃

建立了顶空-气相色谱/质谱(HS-GC/MS)法测定溶剂型木器涂料中卤代烃含量的方法。采用HS-GC/MS测定了二氯甲烷、1,1-二氯乙烷、三氯甲烷、1,1,1-三氯乙烷、四氯化碳、1,2-二氯乙烷、1,1,2-三氯乙烷7种化合物,样品经丙酮稀释,外标法定量。结果表明:7种卤代烃含量在0.05~500 mg/L范围内线性关系良好,相关系数(r2)大于0.994,定量限为0.05~0.2 mg/kg。加标回收率64.4%~107.7%,相对标准偏差为4.1%~11%(n=6)。方法已用于溶剂型木器涂料中卤代烃的定性、定量分析。     

凝胶色谱-气相色谱-串联质谱法筛查茶叶中27种禁用农药

建立了茶叶中27种国家禁用农药的气相色谱-串联质谱分析方法。以27种国家禁用农药为目标分析物,样品经环己烷-乙酸乙酯超声提取、凝胶渗透色谱净化后进行定性和定量分析。方法检出限为0.02~2.82μg/kg,方法定量限为0.07~9.40μg/kg,在0.01~0.20 mg/L范围内方法线性相关系数均大于0.991,75%以上的农药的回收率在70%~110%之间,相对标准偏差在0.53%~7.1%之间。方法适用于茶叶中多种农药残留的检测分析。     

家具白乳胶中苯系物含量测定

建立了气相色谱内标法测定家具白乳胶中苯系物含量的方法。样品中苯系物经甲醇提取、离心,上清液用60 m EN-20色谱柱分离,气相色谱检测,内标法定量。优化条件下苯系物回收率在96.84%~103.86%,相对标准偏差(RSD)为0.79%~2.28%,定量下限2.4~2.9 mg/L。方法操作简单,准确度和精密度较高,是一种检测白乳胶产品中苯系物含量的有效方法。     

气相色谱―质谱法测定仿真饰品中磷酸酯类增塑剂含量

建立了仿真饰品中6种磷酸酯类增塑剂含量的气相色谱―质谱测定法。对提取方法、色谱条件及质谱参数进行了研究。结果表明,采用正己烷/丙酮(体积比1∶1)微波萃取样品35 min可获得良好的提取效果。所建立的微波萃取―气相色谱―质谱法的定量限为1～2.5 mg/kg,在1～2个数量级浓度范围内,线性相关系数R2在0.999以上,在三个添加水平下回收率在86.63%～98.13%之间。对市售9种塑料仿真饰品的测定结果表明磷酸酯的存在风险极低。     

热解析–气相色谱–质谱法测定汽车零部件及内饰材料中挥发性有机化合物

将待测材料直接放在热解析管中,用热脱附–气相色谱–质谱法对挥发性有机化合物的含量进行检测。经试验优化,热解析时间选择为30 min。在10~500μg/m L范围内,7种苯系物的质量浓度与对应色谱峰面积线性相关,相关系数为0.998 3~0.999 6。方法的加标回收率为80.3%~98.1%,测定结果的相对标准偏差为3.37%~5.42%(n=7)。该方法具有操作简便、提取效率高和全自动化等优点,适用于汽车零部件及内饰材料中挥发性有机化合物的检测。     

GC-MS法测定氧化型染发剂中的苯二胺

建立了气相色谱-质谱同时测定氧化型染发剂中邻苯二胺、间苯二胺和对苯二胺的方法。以乙酸乙酯提取氧化型染发剂中苯二胺,用气相色谱-质谱方法进行定性和定量分析。该方法对氧化型染发剂中的3种苯二胺的检出限为20 mg/kg,线性范围为0.2~10 mg/L,线性相关系数为0.999 2~0.999 9。方法的回收率为75%~110%,满足氧化型染发剂中3种苯二胺检测的需要。     

超声萃取-气相色谱-质谱法检测塑料玩具中8种邻苯二甲酸酯类增塑剂

建立了气相色谱-质谱法（GC-MS）同时测定玩具中8种邻苯二甲酸酯化合物的方法.利用四氢呋喃提取塑料玩具中邻苯二甲酸酯化合物,超声提取30 min,经乙腈沉淀,采用GC-MS外标法进行定量检测.结果表明,8种邻苯二甲酸酯线性范围为0.5~10 mg/L,相关系数均大于0.995,方法检出限为1.14~13.65 mg/kg,平均回收率为89.2%~103.8%,相对标准偏差为1.41%~4.93%.方法简单、快速、准确,可用于塑料玩具中邻苯二甲酸酯的检测.     

气相色谱法测定多泥沙水体中挥发性卤代烃

应用气相色谱-电子捕获检测器(ECD)检测法测定了多泥沙的黄河水样中挥发性卤代烃。用吹扫捕集法作试样预处理。为降低卤代烃在水溶液中的溶解度,采用了饱和氯化钠溶液作为专用电解质,因而也提高了方法的灵敏度,按优化的分析条件,对4种卤代烃作了试验。结果表明,四者分离良好,检出限在0.01~0.20μg.L-1之间。加标回收率在95.0%~103.0%之间。     

凝胶渗透色谱-固相萃取净化/气相色谱-串联质谱法测定动物性食品中167种农药残留

建立了肉类、水产类等动物性食品中167种农药残留的气相色谱-串联质谱检测方法。样品匀浆后,采用乙腈提取,以凝胶渗透色谱和Carb-NH2萃取柱联合净化,气相色谱-串联质谱检测,外标法定量。167种农药的响应在1~200μg/L质量浓度范围内线性良好,相关系数在0.994以上,各农药的检出限为0.3~3μg/kg,定量下限为1~10μg/kg。以猪肉样品作为代表性基质,进行0.01,0.04 mg/kg 2个水平的加标回收实验,回收率为66.4%~111.5%,相对标准偏差为1.3%~17.8%。本方法准确可靠,灵敏度高,样品净化效果好,能够满足动物性食品中农药多残留的痕量分析要求。     

溶剂型涂料中16种有害物质的气相色谱-质谱同时检测方法

建立了溶剂型涂料中16种有害物质(甲醇、卤代烃、苯系物和游离二异氰酸酯)的GC-MS同时检测方法,研究了乙酸乙酯、正己烷、四氢呋喃和乙腈对各有害物质的提取和分离效果,并对样品前处理和色谱条件进行了优化.样品中加入2-溴丙烷和1,2,4-三氯苯作内标,用乙腈超声萃取并经有机膜过滤后,用.GC-MS进行测定,内标法定量.结...     

新型N-芳基哌嗪取代苯并呋喃衍生物的合成

以5-二甲氨基水杨醛和2-溴-4'-氟苯乙酮为原料,经缩合和取代反应制得中间体6-二乙氨基-2-[4'-(N-哌嗪基)苯甲酰基]苯并呋喃(2);2与卤代烃反应合成了6个新型的N-芳基哌嗪取代苯并呋喃衍生物(4a~4f),收率76%~93%,其结构经1H NMR,13C NMR和HR-MS(ESI-TOF)表征。     

反气相色谱法与Hansen溶解度参数法测定聚乙烯醇溶解度参数及相关热力学性质

采用反气相色谱（IGC）法,以聚乙烯醇（PVA）为固定相,脂肪族、芳香族、醇、酮及卤代烃5类18种化合物为探针分子,研究PVA的溶解性质并获得了PVA在383.15～423.15 K范围内的溶解度参数（δ₂）及相关热力学性质,并与Hansen溶解度参数法（HSP）测得的溶解度参数（δ_T）进行比较。结果表明,5类溶剂对PVA溶解能力的趋势为酮类 >醇类 >卤代烃、芳香类、脂肪族类>脂环族,卤代烃、芳香类和脂肪族类溶剂的溶解能力相似;在测试温度范围内PVA的δ₂随温度升高而增加;采用IGC法外推出室温（298.15 K）下PVA的δ₂为27.69 （J/cm³）^0.5,与HSP法测得室温下PVA的δ_T（27.77 （J/cm³）^0.5）一致。PVA溶解度参数及相关热力学参数的研究为其应用及相关研究提供了定量依据。     

Development of an analytical technique and stability evaluation of 143 C3-C12 volatile organic compounds in Summa canisters by gas chromatography-mass spectrometry

A technique using Summa canisters with cryogenic preconcentration and gas chromatographic-mass spectrometric (GC-MS) detection was developed to determine 143 C3-C12 volatile organic compounds (VOCs) including alkanes, alkenes, aromatics and halohydrocarbons in ambient and indoor air. The method detection limits and practical quantification limits were sensitive at 0.02 and 0.10 ppbv, respectively, and the method precision and accuracy were also satisfactory. The stability of C3-C12 VOC standards at ppbv levels under elevated pressure in canisters was assessed over various time intervals (from 1 week to 4 months after preparation) and most of the compounds were found to be acceptably stable with a mean recovery of 85.6 +/- 9.9% during the course of a 4-month study. However, a small fraction (approximately 6%) of the compounds, including two halohydrocarbons (bromotrichloromethane and benzyl chloride) and six alkenes (2-methylbuta-1,3-diene (isoprene), cis-4-methylpent-2-ene, cis-3-methylpent-2-ene, hept-1-ene, oct-1-ene and styrene) displayed relatively low recoveries in the range 34.6-67.9%. The loss of these compounds is most probably caused by their physical adherence to the active sites of the canister surface, chemical decomposition and/or reactions with other species. The results indicated that one must be cautious in attempting to measure these compounds owing to their instability in canisters. Overall, this analytical technique, which has been used for the determination of the VOCs under study in the toxic air pollutant monitoring network administered by the HKSAR Government, was amenable to the measurement of airborne VOCs collected both outside and inside a semi-confined car park in the present study.     

气相色谱智能优化在卤代烃分析中的应用

本文研究了气相色谱柱温智能优化软件在卤代烃毒物分析中的应用。智能优化使得包含多个卤代烃与烃的混合样品达到了满意的分离效果，保留值预测误差在１．１％以内，吻合程度很好。     

考察不同组成及制备工艺对合金饰品镍释放量的影响

镍被广泛应用于日常使用的合金饰品中,镍的释放会引起皮炎等症状.针对不同组成及制备工艺的合金饰品进行了镍释放量的考察,表明相同基材的合金饰品,随着镍含量的增加,镍释放量增加;相同镍含量的基材,应用冲压工艺制备样品的镍释放量值低于失蜡浇铸工艺制备样品的镍释放量值.贵金属的加入能有效抑制镍释放量.     

Continuous microwave-assisted extraction coupled on-line with liquid-liquid extraction: determination of aliphatic hydrocarbons in soil and sediments

This paper describes a new extraction method for the determination of aliphatic hydrocarbons (AHs) in soil and sediment samples, using continuous microwave-assisted extraction (MAE) combined with liquid-liquid extraction, for clean-up purposes. Analytical determinations were carried out by gas chromatography coupled with impact ionization mass spectrometry. The influence of the experimental conditions was tested using an agricultural soil spiked with standards (stored at 4 degrees C for 1 month) as reference soil. Maximum extraction efficiencies (80-90%) were achieved using 0.1-1.0g of sample, 60microl of water and 3ml of n-hexane (extractant) and 5min of extraction time; less than 70% of the most volatile hydrocarbons (C(9)-C(12)) were recovered since many evaporated during the drying step of the sample. MAE was compared with a conventional extraction method such as Soxhlet and a good agreement in the results was obtained (average recovery percentage value of 105% by comparing MAE against Soxhlet). Quality parameters such as linear range (0.5-800microg/g), limits of detection (LODs) (0.1-0.2microg/g) and precision (RSD, 4-6%) were determined using spiked soil samples. This method was successfully applied to the analysis of aliphatic hydrocarbons (C(9)-C(27) including pristane and phytane) in contaminated real samples.     

Preparative isolation of terpene trilactones from Ginkgo biloba leaves

This study investigated and compared some techniques for the preparative isolation of terpene trilactones, including ginkgolides (GA and GB, etc.) and bilobalide (BB), from Ginkgo biloba leaves. The crude Ginkgo biloba L. extracts (GBE) were prepared using an extractor with solvent refluxing operated under an optimal extraction condition. The extraction yield was 20-23% and the purity of terpene trilactones was about 1.0-1.4 wt%. Before the isolation operations, the extracts were dissolved in de-ionized water. The isolation procedures included the method of liquid-liquid extraction and the method of column chromatography. For the method of liquid-liquid extraction using ethyl acetate as the organic solvent operated under the optimal extraction conditions, the purity, concentration ratio, and yield of terpene trilactones were 13.5-18.0%, 15-16, and >99%. For the method of column chromatography, XAD-7HP, XAD-4, and C-18 adsorbents with different polarities were used as the packing materials. Only for the XAD-7HP column, a part of more polar impurities was efficiently separated with the majority of terpene trilactones by a proper step-gradient elution, which resulted in an efficient isolation: the purity, concentration ratio, and yield of terpene trilactones were approximately 20, approximately 15, and approximately 80%. In comparison, the XAD-7HP column achieved the highest purity, but at the expense of the yield of terpene trilactones; on the contrary, the liquid-liquid extraction method, achieving the highest yield but with a slightly lower purity, was proved to be superior to the method of column chromatography in the current isolation stage.     

Determination of trace amounts of off-flavor compounds in drinking water by stir bar sorptive extraction and thermal desorption GC-MS.

A method for the determination of trace amounts of off-flavor compounds including 2-methylisoborneol, geosmin and 2,4,6-trichloroanisole in drinking water was developed using the stir bar sorptive extraction technique followed by thermal desorption-GC-MS analysis. The extraction conditions such as extraction mode, salt addition, extraction temperature, sample volume and extraction time were examined. Water samples (20, 40 and 60 ml) were extracted for 60-240 min at room temperature (25 degrees C) using stir bars with a length of 10 mm and coated with a 500 microm layer of polydimethylsiloxane. The extract was analyzed by thermal desorption-GC-MS in the selected ion monitoring mode. The method showed good linearity over the concentration range from 0.1 or 0.2 or 0.5 to 100 ng l(-1) for all the target analytes, and the correlation coefficients were greater than 0.9987. The detection limits ranged from 0.022 to 0.16 ng l(-1). The recoveries (89-109%) and precision (RSD: 0.80-3.7%) of the method were examined by analyzing raw water and tap water samples fortified at the 1 ng l(-1) level. The method was successfully applied to low-level samples (raw water and tap water).     

气相色谱–质谱法测定工作场所空气中的5种卤代烃

建立二硫化碳解吸气相色谱–质谱法同时测定工作场所空气中5种卤代烃快速灵敏的分析方法。采用活性炭管采集空气样品,以二硫化碳解吸,应用DB–624色谱柱分离及气相色谱–质谱联用的方法对工作场所空气中的三氯甲烷、四氯化碳、二氯乙烷、三氯乙烯、四氯乙烯5种卤代烃进行同时定性及定量分析。在所选定的条件下,5种卤代烃可实现基线分离,标准工作曲线线性良好,相关系数r≥0.998,加标回收率在93.9%~102.0%之间,测定结果的相对标准偏差小于5%(n=6)。该方法简单、快速,选择性好,灵敏度高,重现性好。