共查询到20条相似文献,搜索用时 15 毫秒
1.
《Analytical letters》2012,45(20):2369-2384
Abstract Pentafluorophenyldimethylsilyl chloride (flophemesyl chloride, F1) is a well known derivatization reagent for improved electron capture detection (ECD) in gas chromatography (GC)(GC-ECD), but it has never been utilized for improved detectability and sensitivity in GC-photoionization detection (GC-PID). We have now utilized a wide variety of flophemesyl alcohol derivatives in order to show a new approach for realizing greatly reduced minimum detection limits (MDL) of virtually all alcohol derivatives in GC-PID analysis. This particular derivatization approach is inexpensive and easy to apply, leading to quantitative or near 100% conversion of the starting alcohols to the expected flophemesyl ethers (silyl ethers). Detection limits can be lowered by 2–3 orders of magnitude for such derivatives when compared with the starting alcohols, along with calibration plots that are linear over 5–7 orders of magnitude. Specific GC conditions have been developed for many flophemesyl derivatives, in all cases using packed columns. Both ECD and PID relative response factors (RRFs) and normalized RRFs have been determined, and such ratios can now be used for improved analyte identification from complex sample matrices, where appropriate. We have attempted to describe in this preliminary report some interesting results and approaches for improved GC-PID detection of a large number of alcohols and alcohol analogs. The method of derivatization is extremely simple to perform, and appears to lead to a single, well-defined product of known structure in 100% yield or thereabouts. Chromatography for typical flophemesylalcohol analytes can be excellent, as in Figure 1, with symmetrical peak shape, little or no tailing, and overall excellent MDLs. With GC-detector-computer interfacing, we are able to obtain both chromatograms and preliminary as well as calculated data within a single 5–10 minute time span27 The total amount of time per analysis will obviously depend on the particular analyte derivative and the chromatography obtained. RRFs and normalized RRFs are quite easy to determine, they are fully reproducible, and can serve as good markers for a particular alcohol and its flophemesyl derivative. In view of the calibration plots possible and MDLs, these overall analytical methods for GC-ECD-PID using flophemesyl derivatization should, we hope, find widespread and ready acceptance and utility by the analytical community. 相似文献
2.
3.
4.
5.
6.
《Analytical letters》2012,45(10):1095-1102
Abstract Poly (crown ether) was employed as a catalyst of derivatization of lower fatty acids to the p-bromophenacyl esters for gas chromatographic determination of them. The esterification reaction proceeds quantitatively under mild conditions, i.e. at room temperature and within 30 min. The poly (crown ether) did not interfere with the gas chromatogram of the esters unlike monomeric crown ethers. Normal fatty acid (C1-C6) and the isomers could be determined simultaneously near to the detection limit of FID. 相似文献
7.
柱前衍生化毛细管气相色谱法测定土壤中井冈霉素A残留 总被引:1,自引:0,他引:1
建立了土壤中井冈霉素A残留的柱前衍生化气相色谱分析方法。每10 g土壤样品使用40 mL10%氨水振荡提取60 min,不需要其它净化处理。浓缩吹干后采用N,O-双(三甲基硅烷基)乙酰胺(BSA)对井冈霉素A衍生化反应并进行毛细管气相色谱(FID)分析。井冈霉素A衍生物在4.4~71 mg/L范围内呈良好的线性关系(r=0.9983);方法的添加回收率在94.8%~101.6%之间;相对标准偏差为1.1%~2.9%;方法的最小检出浓度为0.20 mg/kg。 相似文献
8.
衍生化毛细管气相色谱法分离测定山梨醇和甘露醇 总被引:7,自引:0,他引:7
采用乙酸酐为衍生化试剂,吡啶为溶剂和催化剂,将山梨醇和甘露醇转化成易恽发的糖醇乙酰酯衍生物。用苯基氰丙基聚硅氧烷(BPX-70)毛细管色谱柱分离分析,使同分异构体的六元糖醇得到了很好的分离,并用内标法定量。山梨醇甘露醇的线性范围均为2.50g/L-12.5g/L,检测限分别为0.60ng和0.68ng。 相似文献
9.
合成了用于气相色谱(GC)的手性衍生化试剂N-七氟丁酰基-L-脯氨酰氯(N-HFB-L-PCl)。各种特性试验表明,N-HFB-L-PCl是灵敏的GC手性衍生化试剂,可直接于水相拆分微量的手性胺对映体。 相似文献
10.
气相色谱法分离检定血中八种氨基甲酸酯 总被引:5,自引:0,他引:5
采用国产C_18往固相提取血中八种氨基甲酸酯,用乙酸乙酯洗脱,用气相色谱分离检定,用气相色谱/质谱进行确证。此法灵敏度为1~2μg/mL血,最低检出限为20~40ng,回收率在62~92%之间。 相似文献
11.
建立衍生化气相色谱法测定非离子型X-CT造影剂碘海醇中间体3-氨基-1,2-丙二醇的含量.将试样经过三氟乙酸酐(TFAA)在50℃下衍生30 min后,用配有FID检测器的气相色谱仪SE-54毛细管柱(30 m×0.25 mm×0.25μm)进行测定,在选定的实验条件下,测定的相对标准偏差为0.921%,加样回收率为99.2%.结果重现性好,准确度高,方法简便易行. 相似文献
12.
The isoflurane content was determined by using a 93mm × 2.1m glass GC column packed with 25%PEG-20M/Chromosorb P AW-DMCS(80~100 mesh)and flame ionization detector,and the column temperature was 70℃.The quantitative determination was performed with trichloromethane as internal standard. 相似文献
13.
衍生化气相色谱法测定盐酸芬氟拉明片的纯度 总被引:4,自引:0,他引:4
应用衍生化气相色谱法测定盐酸芬氟拉明片的纯度。样品溶解后经碱化乙酸乙酯提取 ,以盐酸美西律作内标 ,提取液用三氟乙酸酐进行酰化衍生化 ,衍生化产物在 5 %SE 30的色谱柱上分析 ,用氢火焰离子化检测器 (FID)检测。实验结果表明 ,芬氟拉明的质量浓度在 0 1g/L~ 0 5 g/L范围内线性良好 (r =0 9996 ) ;芬氟拉明与内标美西律的分离度大于 4;理论塔板数以芬氟拉明峰计大于 2 0 0 0 ;方法的精密度好 ,相对标准偏差 (RSD)为 1 4% (n=7) ;平均回收率为 (10 0 2± 2 2 ) % (n =6 ) ;检测限为 8ng。用该方法得到的结果灵敏、准确、重复性好。 相似文献
14.
15.
研究了致幻性安非他明类药物3,4-亚甲二氧基甲基安非他明(MDMA)和3,4-亚甲二氧基安非他明(MDA)的乙酰化、三氟乙酰化、五氟丙酰化、七氟丁酰化、二氯乙酰化、一氯二氟乙酰化、五氟苯甲酰化、五氟苯磺酰化和二硝基苯甲酰化的衍生化反应条件,发现除了乙酰化之外所研究的各种衍生化反应均可用5μL酸酐或酰氯在环己烷中于20℃10 m in内完成。乙酰化可用20μL乙酸酐在60℃30 m in内完成。在此基础上建立了尿中MDMA和MDA的各种衍生化的氮磷检测气相色谱(GC/NPD)分析方法。方法操作简便快速,绝大多数方法的检出限低于10μg/L,其中二氯乙酰化、一氯二氟乙酰化、五氟苯甲酰化、五氟苯磺酰化和二硝基苯甲酰化的GC/NPD分析方法未见文献报道。对一些灵敏的方法进行了线性关系和回收率的考察,结果满意。 相似文献
16.
采用三氟乙酸水解豌豆根尖粘液中的多糖,衍生化后用气相色谱分离测定6种单糖.实验表明,根尖粘液用三氟乙酸水解并乙酰化,采用OV-17石英毛细管色谱柱(35 m×0.32 mm, 0.33 μm),利用气相色谱法对6种单糖进行分离测定,6种糖全部达到基线分离,总分析时间为42 min.用保留时间定性,外标法定量.方法线性范围为0.0025~2.5 g/L,各标准曲线相关系数r>0.9991; 检出限0 0216~0.1578 mg/L,加样回收率为96.7%~107.4%.实验结果表明,本方法可有效测定逆境胁迫下植物根尖粘液中的糖类物质. 相似文献
17.
气相色谱/质谱与气相色谱/原子发射光谱联用分析多氯邻羟基二苯醚类化合物 总被引:3,自引:0,他引:3
利用气相色谱/质谱(GC/MS)确定三氯新经多相催化加氢后所得的氯代邻羟基二苯醚类化合物的分子组成和结构;以正二十烷为内标物利用气相色谱/原子发射光谱(GC/AED)碳元素(496nm)检测通道,直接得到氯代邻羟基二苯醚类化合物中碳元素的质量,再根据分子式对组分定量。同时选择氯(479nm)和氧(171nm)通道,以三氯新为内标物定量组分中的氯和氧元素的质量。不同检测通道和不同内标物对同一组分所得定量结果基本一致。因而,对难以全部获得标准样品的复杂体系(如含有多种杂原子、同分异构体以及化学反应过程产物),GC/MS和GC/AED联用能够得到准确、可靠的定性和定量结果。 相似文献
18.
19.
液液微萃取-甲基衍生化/气相色谱法对水中氯代酸除草剂的测定 总被引:4,自引:0,他引:4
在pH大于12的条件下使水样中的氯代除草剂全部水解为盐,用正己烷和甲基叔丁基醚混合溶剂提取有机杂质,再在酸性条件下经5 mL甲基叔丁基醚提取,重氮甲烷甲基衍生化30 min后用带微电子捕获检测器的毛细管气相色谱分析,以4,4-二溴八氟联苯为内标物进行定量.茅草枯、麦草威、2,4-D、五氯苯酚的质量浓度分别在5.0 ~500、1.0 ~200、5.0 ~500、0.5 ~100 μg/L范围内与色谱峰面积呈良好的线性关系(r= 0.994 5 ~0.998 0),检出限分别为1.0、0.5、1.0、0.1 μg/L.用该法测定南京玄武湖水样中的茅草枯,其质量浓度为7.1 μg/L,4种被测组分在高、中和低添加水平下的回收率分别为102% ~105%、96% ~110%、87% ~109%.同时建立了一种生产重氮甲烷的新原料--N-亚硝基-N-甲基脲的简易方法. 相似文献