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气相色谱-双柱双电子捕获检测器测定土壤及沉积物中23种有机氯农药 总被引:1,自引:0,他引:1
建立了微波萃取,弗罗里硅土固相萃取柱及铜粉除硫净化,双柱双电子捕获检测器(ECD)-气相色谱法(GC)测定5种不同质地土壤及5处不同来源沉积物中的23种有机氯农药(OCPs)。采用内标法定量,在0.005~0.5 mg/L的质量浓度范围内,替代物和各种农药标准品的线性相关系数(r2)均大于0.997。5种土壤及5处沉积物中23种OCPs的平均加标回收率分别为50%~119%和52%~120%,相对标准偏差分别为0.9%~16.1%(n=6)和0.3%~28.4%(n=6),检出限为0.00005~0.0005 mg/kg。结果表明,该方法重现性好、灵敏度高、线性关系好,可以满足简便、快速、准确测定农药残留的要求,可大范围推广使用。 相似文献
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陈蓓蓓 《理化检验(化学分册)》2014,(6):675-680
采用双柱和双检测器-气相色谱法测定了污染土壤中23种有机氯农药(OCP′s)和7组亚老哥尔。取20g自然风干粒径小于0.30mm的土壤样品,用二氯甲烷超声萃取3次,提取液于40℃吹氮浓缩并转换成正己烷溶液,浓缩至1mL。仅测定亚老哥尔时用浓硫酸净化法;仅测定OCP′s时用弗罗里硅土小柱或硅胶净化;同时测定OCP′s和亚老哥尔时,用硅胶小柱分步洗脱净化。样品的浓缩液中如存在大分子干扰物,则用GPC净化。经净化的试液浓缩至1mL供气相色谱分析。OCP′s根据标准溶液在双柱上的保留时间定性,外标法定量;对亚老哥尔,每组选3~5个校准峰,与基准谱图拟合定性,以校准峰的平均值进行定量。OCP′s和亚老哥尔的检出限依次为0.001,0.002 5~0.005mg·kg-1,平均回收率依次在82.1%~103%,83.5%~94.7%之间。 相似文献
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将采集的土壤样品混匀并除去混入的异物,置于冷冻干燥机中脱水后研磨混匀,封存于干燥器中备用。取此样品20.00g,与硅藻土3.00g和硅镁吸附剂3.00g掺拌均匀。在加速溶剂萃取(ASE)仪的萃取池的底部铺垫硅镁吸附剂3.00g,将上述样品混合物定量移入于此池中,于其上面铺盖一层石英砂和加盖一张滤纸片。按设定条件以体积比为1∶1的二氯甲烷-正己烷混合溶液作为萃取溶剂,在90℃萃取2次。将所得萃取液合并并吹氮浓缩至体积小于1mL,加正己烷定容至1.0mL。此溶液作为试液进行气相色谱分析,测定其中19种有机氯农药(OCPs)的含量。色谱分析中,进样量为1.0μL,选择HP-5LTM和DB 1701LTM两种极性不同的色谱柱,按程序升温条件对目标物进行分离。采用双电子捕获检测器(ECD),前ECD接在HP-5LTM色谱柱后,后ECD接在DB 1701LTM色谱柱后,经两种色谱柱分离,测定所制得标准曲线的线性范围均有两个相同的区段,即5~100μg·L-1和100~1 000μg·L^-1。19种OCPs的检出限(3.143s)为0.15~0.56μg·kg^-1。如果目标物在两种色谱柱上的测定结果差异大于5倍,则判定此结果为假阳性;如差异小于5倍,则确定该化合物存在,并以数值较小者为测定结果。精密度试验测得目标物测定值的相对标准偏差(n=6)为2.7%~15%。用本方法分析了土壤标准物质(CRM818-50G),所测得19种OCPs的结果均在认定值范围内。 相似文献
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通过比较不同固相萃取柱对沉积物提取液的净化效果和对气相色谱微电子捕获检测器(GC-ECD)基线的影响,建立了沉积物中15种有机氯农药的气相色谱分析方法。10 g风干的沉积物样品加入1 g Cu粉和3 g无水Na2SO4用100 m L石油醚-丙酮(1:1,V/V)于索氏抽提系统提取60个循环,提取液用石墨化炭黑(Pesticarb)固相萃取柱净化,GC-ECD测定。方法学结果表明,沉积物中15种有机氯农药具有良好的线性关系,检出限0.035~0.464μg/kg,定量限0.12~1.55μg/kg,经Pesticarb-SPE净化15种有机氯农药平均回收率为94.8%,相对标准偏差为1.6%~6.8%。方法应用于西溪湿地表层和底层沉积物监测,32个样品中,除了艾氏剂,其余农药均有不同程度的检出。 相似文献
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将不同材质塑料样品用四氢呋喃溶解,再用甲醇沉淀杂质大分子后高速离心过滤,各有机锡在乙酸-乙酸钠缓冲溶液中与四乙基硼酸钠反应生成有机锡的乙基化衍生物,经正己烷萃取后进行气相色谱定性、定量分析,并对衍生化条件(如衍生时间、酸度、衍生试剂)进行优化。用双柱-质谱和火焰光度双检测器/气相色谱法测定了PVC,PC,PS,AS及ABS不同塑料样品中的二甲基锡、三甲基锡、二乙基锡、一丁基锡、二丁基锡、四丁基锡、二辛基锡、三环己基锡、二苯基锡和三苯基锡共10种有机锡化合物。采用外标法定量,在0.01~10 mg·L-1浓度范围内,各有机锡化合物均呈良好线性,其相关系数(r)均大于0.999。测得PVC,PS,ABS不同塑料样品中10种有机锡的回收率为75.1%~110.1%,相对标准偏差(n=6)小于10%,检出限为0.005~0.037 mg/kg。该方法重复性好,操作简单,灵敏度高,能广泛应用于各种塑料制品中多种有机锡的检测。 相似文献
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超声波萃取-分散固相萃取净化-气相色谱电子捕获法测定土壤或底泥中的多氯联苯 总被引:2,自引:0,他引:2
采用超声波萃取、分散固相萃取净化结合气相色谱电子捕获检测法,建立了快速测定环境土壤或底泥中7种指示性多氯联苯(Polychlorinated biphenyls,PCBs)的方法.根据提取液的颜色,灵活选择是否增加浓H2SO4净化步骤,并对分散固相萃取净化过程中吸附剂的种类和用量进行了优化.当提取液颜色基本无色透明时,仅选用150 mgⅣ-丙基乙二胺(Primary secondary amire,PSA)吸附剂进行分散固相萃取净化(即一步净化),否则提取液先经过浓H2SO4净化,再采用100 mg PSA吸附剂进行分散固相萃取净化(即两步净化).整个分散固相萃取净化过程不超过5min,前处理时间显著缩短.结果表明,在1.25 ~ 100 μg/L浓度范围内,7种PCBs峰面积与浓度呈线性相关,相关系数为0.9990 ~0.9999,检出限为0.02 ~0.03 μg/kg,样品经两步净化和一步净化时,7种PCBs不同浓度加标水平回收率分别为72% ~ 107%和88% ~ 115%,相对标准偏差分别为3.5% ~5.8%和3.7%~6.9%(n=5),已成功应用于舟山朱家尖某菜地土壤样品和岱衢洋海域底泥样品检测,且检测结果与国家标准方法保持一致.本方法简单快速,高效,基体干扰小,灵敏度、准确度、精密度均满足土壤或底泥中PCBs的定量分析要求. 相似文献
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Luigi Torreti Anselmo Simonelia Angelo Dossena Emilio Torreti 《Journal of separation science》1992,15(2):99-101
Organochlorine pesticide residues have been extracted from samples of animal feed by a solid phase extraction clean-up procedure using an octadecyl-bonded column. The proposed method gave recoveries ranging from 70 to 100 % for ppb levels of the fifteeen pesticides studied. Analytes were identified by dual-column capillary gas chromatography employing DB-1 and DB-1701 columns in parallel; identities were confirmed by calculation of retention indexes with the cubic spline interpolation method. 相似文献
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Ultrasonic solvent extraction of the organochlorine pesticides (OCP) including α-, β-, γ- and Δ-hexachlorocyclohexane (HCH), heptachlor, aldrin, o,p′-DDE, dieldrin, p,p′-DDE, p,p′-DDT, methoxychlor, mirex from soil is reported. The extraction procedure was optimized with regard to the solvent type, amount of solvent, duration of sonication and number of extraction steps. Determination of pesticides was carried out by gas chromatography (GC) equipped with electron capture detection (ECD). Twice ultrasonic extraction using 25 mL of a mixture of petroleum ether and acetone (1/1 v/v) for 20 min of sonication showed satisfactory extraction efficiency. Recoveries of pesticides from fortified soil samples are over 88% for three different fortification levels between 15 and 200 μg kg−1, and relative standard deviations of the recoveries are generally below 6%. Real soil samples were analyzed for OCP residues by optimized ultrasonic solvent extraction and shake-flask as well as soxhlet extraction technique. Investigated all extraction methods showed comparable extraction efficiencies. Optimized ultrasonic solvent extraction is the most rapid procedure because the use of time in ultrasonic extraction was considerably reduced compared to shake-flask and soxhlet extraction. 相似文献
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土壤中多种有机氯及拟除虫菊酯类农药的GC-ECD测定 总被引:1,自引:0,他引:1
气相色谱法同时测定土壤中多种有机氯及拟除虫菊酯类农药。对土壤的分析结果:有机氯农药的检出限0.001~0、003μg/mL,拟除虫菊酯类农药检出限0.008~0.02μg/mL,线性相关系数0.9978~0.9999。用y(石油醚):V(丙酮)=3:1超声波提取,有机氯农药回收率94.2%~124.0%,相对标准偏差为3.3%~8.8%(n=5);拟除虫菊酯类农药回收率95.2%~118.3%,相对标准偏差为5.7%~7.1%(n=5);方法适用于土壤样品中农药残留测定。 相似文献
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The simultaneous analysis of α-HCH, β-HCH, γ-HCH, HCB, p,p′-DDD, p,p′-DDT, p,p′-DDE, o,p′-DDT, mirex, dieldrin and 62 chlorobiphenyl congeners on two parallel capillary GC columns of different polarity is described for nine Mediterranean fish species. Ten commercially available columns with stationary phases completely characterized in respect of their PCB elution patterns were considered for dual-column GC-ECD analysis. The combination of a 60 m × 0.25 mm i.d. column coated with a 0.25 μm film of 50% diphenyl dimethylsiloxane and a series combination of a 25 m × 0.25 mm i.d. column coated with a 0.25 μm film of 5% diphenyl dimethylsiloxane with a 25 m × 0.22 mm i.d. column coated with a 0.10 μm film of 1, 10-dicarba-closo-dodecarborane dimethylpolysiloxane furnished the highest number of separated chlorobiphenyl congeners (104). The dual-column GC system performed with high stability and reproducibility over a broad concentration range (1–3000 ng/g lipid) of the organochlorine compounds in the investigated fish. 相似文献
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Barriada-Pereira M González-Castro MJ Muniategui-Lorenzo S López-Mahía P Prada-Rodríguez D Fernández-Fernández E 《Journal of chromatography. A》2004,1061(2):133-139
A method to determine 21 organochlorine pesticides (OCPs) in tree leaves [chestnut (Castanea sativa), hazel (Corylus avellana), oak (Quercus robur) and walnut tree (Juglans regia)] based on microwave-assisted extraction (MAE) followed by solid-phase extraction (SPE) clean-up is described. After extraction with hexane:acetone (50:50), four different sorbents (Florisil, tandem Florisil + alumina, silica and ENVI-Carb) were assayed for the clean-up step. Pesticides were eluted with 5 mL of hexane:ethyl acetate (80:20) and determined by gas chromatography and electron capture detection (GC-ECD). Carbon was the sorbent, which provided colourless eluates and chromatograms with less interferent compounds. Analytical recoveries obtained were ca. 100% for all the studied pesticides with this sorbent. 相似文献
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Summary The use of the solid-phase extraction technique for the rapid sample preparation of organochlorine pesticides is described.
Samples were simultaneously extracted, cleaned, and fractionated by the solid-phase extraction method and a further separation
and determination of extracted fractions was carried out by gas chromatography with either an electron capture or a Hall electrolytic
conductivity detector. The percent recovery of the extracted seven pesticides was compared to that of the conventional liquid-liquid
extraction method. The analytical figures of merit., chromatograms, and statistic data are reported. The application of this
method was demonstrated by a real fish sample determination with mass spectra for confirmation of Kepone detection. 相似文献
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Prediction of the optimal extraction solvent based on the solubility parameter to extract the typical organochlorine pesticides from Jiangxi red soil was reported in this paper. Hildebrand solubility parameters, including dispersion coefficient (δd), polarity (δp) and hydrogen bonding (δh), of extraction solvents (including hexane, dichloromethane, hexane/methanol (4:1, v/v), hexane/acetone (1:1, v/v), hexane/dichloromethane (1:1, v/v) and organochlorine pesticides were calculated using group contribution method. The solvents, such as hexane/methanol (4:1, v/v) and hexane/acetone (1:1, v/v) were selected as ideal extraction solvents to extract o,p′-DDT o,p′-DDE and o,p′-DDD with high recoveries (>82%), furthermore, these solvents can be used to extract α-endosulfan, Endrin and HCB with the reliable recoveries (>75%). The estimated finding by solubility parameters was supported by the results of soxhlet extraction. 相似文献