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1.
固相萃取气相色谱法测定水果中克菌丹和灭菌丹   总被引:1,自引:0,他引:1  
采用硅镁吸附剂和硅胶作为混合固相萃取的净化方法,建立了固相萃取气相色谱法同时测定水果中克菌丹和灭菌丹的分析方法。研究了多种固相萃取柱和不同洗脱溶剂对克菌丹和灭菌丹保留行为的影响,优化了固相萃取净化方法及样品提取方法的分析条件。用GC-ECD检测,两种农药在0.05~2.0mg/L浓度范围内呈线性关系,相关系数大于0.997。苹果中4个浓度克菌丹和灭菌丹的加标回收率分别在100%~111%和104%~113%之间,RSD在3.0%~7.2%和2.8%~4.2%之间。在菠萝、草莓、梨和橙子中,克菌丹的平均回收率和RSD分别在95.6%~112%和2.5%~7.5%之间;灭菌丹在82.5%~96.4%和3.3%~8.0%之间,克菌丹和灭菌丹的方法检出限分别为0.012mg/kg和0.0056mg/kg。  相似文献   

2.
采用硅镁吸附剂和硅胶作吸附剂,建立了固相萃取-高效液相色谱法同时测定苹果中残留的克菌丹和灭菌丹的分析方法。研究了甲醇-乙腈-水(含0.1 mmol/L乙酸-乙酸钠缓冲溶液(pH 3.80))三元体系下克菌丹和灭菌丹的最佳分离条件,在波长210 nm下检测,克菌丹和灭菌丹的线性范围为0.40~8.00 mg/kg,线性相关系数均大于0.9999;最低检出限克菌丹为0.27 mg/kg、灭菌丹为0.20 mg/kg;保留时间的相对标准偏差(RSD)≤0.60%。苹果样品中3个添加水平的平均加标回收率为克菌丹69.3%~106%,RSD为3.7%~4.7%;灭菌丹101%~108%,RSD为1.3%~5.4%。  相似文献   

3.
分散液相微萃取-气相色谱联用分析水样中菊酯类农药残留   总被引:22,自引:6,他引:16  
臧晓欢  王春  高书涛  周欣  王志 《分析化学》2008,36(6):765-769
将分散液-液微萃取(DLLME)与气相色谱-电子俘获检测(GC-ECD)技术相结合,建立了高灵敏度测定水样中7种菊酯类农药残留的新方法。对影响萃取富集效率的因素进行优化,萃取条件选定为:在5.0mL样品溶液中加入10.0μL氯苯和1.0mL丙酮,分散混匀后,以5000r/min离心5min,吸出萃取溶剂氯苯直接进样分析。在优化条件下7种菊酯类农药的富集倍数高达708~1087倍。以α-六六六为内标,7种菊酯类农药在0.8~600μg/L范围内具有良好的线性关系,线性相关系数在0.9990~0.9999之间;检出限为0.04~0.10μg/L(S/N=3)。本方法已应用于自来水、井水及河水等实际水样的分析,平均加标回收率在76.0%~116.0%之间;相对标准偏差在3.1%~7.2%之间。方法具有操作简单、富集效率高和灵敏度高等特点,可满足水样中菊酯类农药残留的检测要求。  相似文献   

4.
建立了环境水样中克菌丹残留量的固相微萃取-气相色谱-串联质谱联用(SPME-GC-MS/MS)检测方法.通过优化固相微萃取的条件对水样中的克菌丹进行富集,分析结果表明克菌丹在0.10~5.00 mg/L的质量浓度范围内线性关系良好,相关系数r2大于0.99,对农田灌溉水进行加标回收率试验,测定的低、中、高3种不同添加浓度的平均回收率分别为75.7%、79.1%和83.1%,相对标准偏差(RSD)在2.0%~3.4%范围内,检出限(LOD)为7.98μg/L.与传统溶剂萃取农药残留的方法相比,具有前处理简便、无溶剂污染等优点,同时方法准确度和精密度较好,可作为环境水样中克菌丹残留量的监测.  相似文献   

5.
建立了使用固相萃取-气相色谱/质谱联用结合同位素稀释技术准确测定3种茶叶(红茶、绿茶和普洱茶)中敌菌丹、克菌丹、灭菌丹、百菌清和苯氟磺胺等杀菌剂农药残留的新方法。茶叶试样中加入同位素内标D6-克菌丹,经乙腈匀浆提取,提取液离心后取上清液经Forisil固相萃取柱浓缩、净化。GC-MS采用选择离子监测(SIM)模式进行定性定量分析,内标法定量。方法的添加回收率为74.1%~100.6%;相对标准偏差为1.2%~12%;6种农药的检出限为0.002~0.14μg/mL。  相似文献   

6.
环境水样中百菌清残留的单滴微萃取-反相液相色谱测定   总被引:7,自引:1,他引:6  
应用单滴微萃取(SDME)-反相液相色谱(RPLC)检测了环境水样中的百菌清残留.优化了单滴微萃取条件:环己烷萃取剂6 μL、单滴体积2 μL、搅拌速率350 r/min、萃取时间40 min、水溶液温度35 ℃、无盐度.水样经单滴微萃取后,使用Hypersil C18柱反相液相色谱分离测定百菌清.反相液相色谱条件:100%甲醇流动相、流速1.0 mL/min、柱温25 ℃、224 nm检测.方法的线性范围、检出限、相对标准偏差和富集倍数分别为1.0 ~50 μg/L、0.02 μg/L、6.1%和427倍.采用该法对环境水样中的百菌清残留进行了测定,环境水样的加标回收率为98% ~106%.  相似文献   

7.
张强  孟梁  邢丽梅 《分析试验室》2011,30(12):55-58
建立了分散液相微萃取与气相色谱电子捕获法检测尿中三种苯并二氮杂(革)类药物的方法.对影响萃取富集效率的因素进行优化,萃取条件选定为:将0.75 mL含有35 μL氯苯的甲醇混合溶液快速注入到5.0mL样品溶液中,分散混匀后,以4000 r/min离心4min,吸取有机相直接进样分析.在优化条件下,三种药物在1~400μ...  相似文献   

8.
建立了原位衍生分散液相微萃取-气相色谱/质谱检测饮用水中痕量三氯生的方法.将含有30.0 μL氯苯(萃取剂)和50.0 μL乙酸酐(衍生试剂)的0.5 mL丙酮(分散剂)作为萃取体系,快速注入到5.0 mL含有K2CO3(0.5%, m/V)的水溶液中.在5000 r/min下离心2 min后,得到(10±0.5) μL沉积相(氯苯),取底部沉积相1.0 μL进行气相色谱/质谱联用仪分析.方法的线性范围为0.05~50 μg/L(r=0.9994),检出限为0.01 μg/L;相对标准偏差2.0%(n=5).利用本方法检测了饮用水中的三氯生,平均加标回收率分别为92.1%和98.4%,结果满意.  相似文献   

9.
将超声辅助乳化与液液微萃取技术结合,建立了水体中人工合成麝香的气相色谱-质谱分析方法.优化前处理条件,包括萃取剂、萃取剂体积、萃取时间、萃取温度及离子强度的选择.结果表明:在10 mL水样中,加入50 μL氯苯作为萃取剂,4 0 MHz超声10 min,混匀,以4000 r/min离心10 min,移取下层有机相进样分析,效果佳.样品的富集倍数可达200倍,8种人工合成麝香在0.005~0.4 μg/L范围内线性关系良好,相关系数均大于0.994;检出限为0.3~0.5 ng/L;水样中加标回收率为96.2%~102.9%;相对标准偏差为2.3%~4.1%.本方法灵敏、快速、准确,可满足环境水样中痕量人工合成麝香监测的质控要求.  相似文献   

10.
建立了气相色谱-质谱快速测定水产品中禾草丹、溴氰菊酯及19种有机氯农药残留的方法.样品经乙腈提取后采用冷冻法去除提取溶液中的大量脂肪,再经氨基固相萃取柱进一步净化后用GC-MS测定.21种农药在0.1~2.0 mg/L范围内线性良好,相关系数r>0.999,样品添加量为0.02~0.1 mg/kg时回收率为79%~114%,相对标准偏差不大于13.5%,检出限为0.5~20 μg/kg(S/N=3).  相似文献   

11.
Microwave-assisted extraction (MAE) and dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) were evaluated for use in the extraction and preconcentration of volatile nitrosamines in meat products. Parameters affecting MAE, such as the extraction solvent used, and DLLME, including the nature and volume of the extracting and disperser solvents, extraction time, salt addition and centrifugation time, were optimized. In the MAE method, 0.25g of sample mass was extracted in 10mL NaOH (0.05M) in a closed-vessel system. For DLLME, 1.5mL of methanol (disperser solvent) containing 20μL of carbon tetrachloride (extraction solvent) was rapidly injected by syringe into 5mL of the sample extract solution (previously adjusted to pH 6), thereby forming a cloudy solution. Phase separation was performed by centrifugation, and a volume of 3μL of the sedimented phase was analyzed by GC-MS. The enrichment factors provided by DLLME varied from 220 to 342 for N-nitrosodiethylamine and N-nitrosopiperidine, respectively. The matrix effect was evaluated for different samples, and it was concluded that sample quantification can be carried out by aqueous calibration. Under the optimized conditions, detection limits ranged from 0.003 to 0.014ngmL(-1) for NPIP and NMEA, respectively (0.12-0.56ngg(-1) in the meat products).  相似文献   

12.
Stir bar sorptive extraction (SBSE) combined with dispersive liquid–liquid microextraction (DLLME) has been developed as a new approach for the extraction of six triazole pesticides (penconazole, hexaconazole, diniconazole, tebuconazole, triticonazole and difenconazole) in aqueous samples prior to GC‐flame ionization detection (GC‐FID). A series of parameters that affect the performance of both steps were thoroughly investigated. Under optimized conditions, aqueous sample was stirred using a stir bar coated with octadecylsilane (ODS) and then target compounds on the sorbent (stir bar) were desorbed with methanol. The extract was mixed with 25 μL of 1,1,2,2‐tetrachloroethane and the mixture was rapidly injected into sodium chloride solution 30% w/v. After centrifugation, an aliquot of the settled organic phase was analyzed by GC‐FID. The methodology showed broad linear ranges for the six triazole pesticides studied, with correlation coefficients higher than 0.993, lower LODs and LOQs between 0.53–24.0 and 1.08–80.0 ng/mL, respectively, and suitable precision (RSD < 5.2%). Moreover, the developed methodology was applied for the determination of target analytes in several samples, including tap, river and well waters, wastewater (before and after purification), and grape and apple juices. Also, the presented SBSE‐DLLME procedure followed by GC‐MS determination was performed on purified wastewater. Penconazole, hexaconazole and diniconazole were detected in the purified wastewater that confirmed the obtained results by GC‐FID determination. In short, by coupling SBSE with DLLME, advantages of two methods are combined to enhance the selectivity and sensitivity of the method. This method showed higher enrichment factors (282–1792) when compared with conventional methods of sample preparation to screen pesticides in aqueous samples.  相似文献   

13.
In the present work a new, simple, rapid and environmentally friendly dispersive liquid–liquid microextraction (DLLME) method has been developed for extraction/preconcentration of some triazole pesticides in aqueous samples and in grape juice. The extract was analyzed with gas chromatography–flame ionization detection (GC–FID) or gas chromatography–mass spectrometry (GC–MS). The DLLME method was performed in a narrow-bore tube containing aqueous sample. Acetonitrile and a mixture of n-hexanol and n-hexane (75:25, v/v) were used as disperser and extraction solvents, respectively. The effect of several factors that influence performance of the method, including the chemical nature and volume of the disperser and extraction solvents, number of extraction, pH and salt addition, were investigated and optimized. Figures of merit such as linearity (r2 > 0.995), enrichment factors (EFs) (263–380), limits of detection (0.3–5 μg L?1) and quantification (0.9–16.7 μg L?1), and relative standard deviations (3.2–5%) of the proposed method were satisfactory for determination of the model analytes. The method was successfully applied for determination of target pesticides in grape juice and good recoveries (74–99%) were achieved for spiked samples. As compared with the conventional DLLME, the proposed DLLME method showed higher EFs and less environmental hazards with no need for centrifuging.  相似文献   

14.
A simple, rapid, efficient, and environmentally friendly method for the determination of five triazine herbicides in water and soil samples was developed by using dispersive liquid-liquid microextraction (DLLME), coupled with high performance liquid chromatography-diode array detection (HPLC-DAD). The water samples were directly used for DLLME extraction. For soil samples, the target analytes were first extracted by water-methanol (99:1, v/v). In the DLLME extraction method, chloroform was used as an extraction solvent, and acetonitrile as a dispersive solvent. Under the optimum conditions, the enrichment factors of DLLME were in the range between 183-221. The linearity of the method was obtained in the range of 0.5-200 ng/mL for the water sample analysis, and 1-200 ng/g for the soil samples, respectively. The correlation coefficients ranged from 0.9968 to 0.9999. The limits of detection were 0.05-0.1 ng/mL for the water samples, and 0.1-0.2 ng/g for the soil samples. The proposed method has been successfully applied to the analysis of target triazine herbicides (simazin, atrazine, prometon, ametryn, and prometryn) in water and soil samples with satisfactory results.  相似文献   

15.
A new microextraction technique termed dispersive liquid-liquid microextraction (DLLME) was developed. DLLME is a very simple and rapid method for extraction and preconcentration of organic compounds from water samples. In this method, the appropriate mixture of extraction solvent (8.0 microL C2Cl4) and disperser solvent (1.00 mL acetone) are injected into the aqueous sample (5.00 mL) by syringe, rapidly. Therefore, cloudy solution is formed. In fact, it is consisted of fine particles of extraction solvent which is dispersed entirely into aqueous phase. After centrifuging, the fine particles of extraction solvent are sedimented in the bottom of the conical test tube (5.0 +/- 0.2 microL). The performance of DLLME is illustrated with the determination of polycyclic aromatic hydrocarbons (PAHs) in water samples by using gas chromatography-flame ionization detection (GC-FID). Some important parameters, such as kind of extraction and disperser solvent and volume of them, and extraction time were investigated. Under the optimum conditions the enrichment factor ranged from 603 to 1113 and the recovery ranged from 60.3 to 111.3%. The linear range was 0.02-200 microg/L (four orders of magnitude) and limit of detection was 0.007-0.030 microg/L for most of analytes. The relative standard deviations (RSDs) for 2 microg/L of PAHs in water by using internal standard were in the range 1.4-10.2% (n = 5). The recoveries of PAHs from surface water at spiking level of 5.0 microg/L were 82.0-111.0%. The ability of DLLME technique in the extraction of other organic compounds such as organochlorine pesticides, organophosphorus pesticides and substituted benzene compounds (benzene, toluene, ethyl benzene, and xylenes) from water samples were studied. The advantages of DLLME method are simplicity of operation, rapidity, low cost, high recovery, and enrichment factor.  相似文献   

16.
Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) was evaluated for the simultaneous determination of five chlorophenols and seven haloanisoles in wines and cork stoppers. Parameters, such as the nature and volume of the extracting and disperser solvents, extraction time, salt addition, centrifugation time and sample volume or mass, affecting the DLLME were carefully optimized to extract and preconcentrate chlorophenols, in the form of their acetylated derivatives, and haloanisoles. In this extraction method, 1mL of acetone (disperser solvent) containing 30μL of carbon tetrachloride (extraction solvent) was rapidly injected by a syringe into 5mL of sample solution containing 200μL of acetic anhydride (derivatizing reagent) and 0.5mL of phosphate buffer solution, thereby forming a cloudy solution. After extraction, phase separation was performed by centrifugation, and a volume of 4μL of the sedimented phase was analyzed by GC-MS. The wine samples were directly used for the DLLME extraction (red wines required a 1:1 dilution with water). For cork samples, the target analytes were first extracted with pentane, the solvent was evaporated and the residue reconstituted with acetone before DLLME. The use of an internal standard (2,4-dibromoanisole) notably improved the repeatability of the procedure. Under the optimized conditions, detection limits ranged from 0.004 to 0.108ngmL(-1) in wine samples (24-220pgg(-1) in corks), depending on the compound and the sample analyzed. The enrichment factors for haloanisoles were in the 380-700-fold range.  相似文献   

17.
A dispersive liquid–liquid microextraction (DLLME) method for separation/preconcentration of ultra trace amounts of Co(II) and its determination with FAAS was developed. The DLLME behavior of Co(II) using Aliquat 336-chloride as ion pairing agent was systematically investigated. The factors influencing the ion pair formation and extraction by DLLME method were optimized. Under the optimized conditions for 150 µL of extraction solvent (carbon tetrachloride), 1.5 mL disperser solvent (acetonitrile) and 5 mL of sample, the enrichment factor was 30. The detection limit was 5.6 µg L?1 and the RSD for replicate measurements of 1 mg L?1 was 1.32 %. The calibration graph using the preconcentration system for cobalt was linear from 40 to 400 µg L?1 with a correlation coefficient of 0.999. The proposed method was successfully applied for determination of cobalt in black tea, paprika and marjoram real samples.  相似文献   

18.
A novel dispersive liquid-liquid microextraction (DLLME) method, coupled to gas chromatography-tandem mass spectrometry (GC-MS/MS), was developed for simultaneously determining the main compounds responsible for cork taint (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) and Brett character (4-ethylguaiacol (EG), 4-ethylphenol (EP), 4-vinylguaiacol (VG) and 4-vinylphenol (VP)) in wines. Optimisation of DLLME procedure was performed by evaluating the type of disperser and extraction solvents and the temperature and salt addition effects. The volumes of disperser and extraction solvents were also optimised by means of a central composite design combined with desirability functions. Under optimum conditions, 5 mL of wine were extracted with an extraction mixture consisting of 1.43 mL of acetone, and 173 μL of chloroform at room temperature. The analytical characteristics of the method were evaluated. Satisfactory linearity (with correlation coefficients over 0.992), repeatability (below 11.6%) and between-days precision (below 11.0%) were obtained for all target analytes. Detection limits attained were at similar levels or even lower than the olfactory threshold of the studied compounds. Finally, the developed method was successfully applied to the analysis of wine samples. To our knowledge, this is the first time that DLLME has been applied to simultaneously determine the compounds responsible for cork taint and Brett character in wine.  相似文献   

19.
将超声波萃取(USE)与分散液-液微萃取(DLLME)联合,利用气相色谱-电子捕获检测(GC-ECD),建立了一种高灵敏度检测水体中菌核净的新方法。对萃取的条件进行优化,选定萃取条件为:在5 mL样品中,注入1 mL丙酮和0.1 mL的四氯化碳混合液,20 Hz超声10 min,振荡混匀后高速离心5 min,移出下层溶剂低温吹干以丙酮定容自动进样分析。在优化条件下,样品的富集倍数可达50倍,检出限为0.001μg/mL,对采于蔬菜地边的水样进行加标回收率实验,平均回收率在81%以上,相对标准偏差在4.3%~7.6%之间,方法可满足水样中菌核净农药残留的检测要求。  相似文献   

20.
The pressurized liquid extraction (PLE) followed by dispersive liquid–liquid micro‐extraction (DLLME) has been developed for extraction of volatile components in tobacco. 35 volatile components were detected by gas chromatography mass spectrometry (GC‐MS). Methanol–methyl tert‐butyl ether (MTBE) (8:2, v/v) was selected as PLE extraction solvent. The optimized DLLME procedure, 3 mL of pure water and 1.0 mL tobacco extract solution, 40 μL of chloroform as extraction solvent, 0.5 mL of acetonitrile as disperser solvent, was validated. Under the optimum conditions, the enrichment factors were in the range of 96‐159. The limits of detection were between 0.14 and 0.33 μg/kg. The repeatability of the proposed method, expressed as relative standard deviation, varied between 4.3 and 7.5% (n = 6). The recoveries of the analytes evaluated by fortification of tobacco samples were in the range of 84.7‐96.4%. Compared with the conventional sample preparation method for determination of volatile components in tobacco, the proposed method was quick and easy to operate, and had high‐enrichment factors and low consumption of organic solvent.  相似文献   

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