气相色谱法测定水和废水中N,N-二甲基甲酰胺和N,N-二甲基乙酰胺

N,N-二甲基甲酰胺和N,N-二甲基乙酰胺都是无色液体,重要的化工原料和性能优良的溶剂,广泛应用于聚氨酯、腈纶、医药、农药、染料、电子等行业,N,N-二甲基甲酰胺和N,N-二甲基乙酰胺对人体有毒,对环境有害。由于N,N-二甲基甲酰胺和N,N-二甲基乙酰胺都与水混溶,沸点较高,较难用溶剂或其它方法将其提取,一般都用直接进水样的方法来测定,但存在峰形不佳、柱子易受污染、需用有机溶剂稀释等不足。本法用Tenax TA作色谱固定相,用长2m、内径3mm玻璃柱直接进水样进行气相色谱的分离和测定,具有峰形佳、分离效果好、分析速度快等特点,用于样品的测定,结果满意。     

气相色谱法测定工业场所空气中的N,N-二甲基甲酰胺和N,N-二甲基乙酰胺

N,N-二甲基甲酰胺(DMF)和N,N-二甲基乙酰胺(DMA)均为无色、有鱼腥味液体,易溶于水及醇等有机溶剂。它们都是重要的化工原料和性能优良的溶剂,广泛应用于聚氨酯、腈纶、医药、农药、燃料、电子等行业。DMF、DMA属低毒类,一般以蒸     

气固顶空-气相色谱法测定纺织品中N,N-二甲基甲酰胺与N,N-二甲基乙酰胺

采用气固顶空-气相色谱法同时测定纺织品中N,N-二甲基甲酰胺(DMF)和N,N-二甲基乙酰胺(DMAC)的残留量。样品经剪碎后,称取0.5g,在120℃顶空温度下加热30min,顶空气体采用CAM色谱柱分离,以氮磷检测器(NPD)进行检测。以基体匹配校正法消除基质效应,外标法定量。DMF、DMAC的质量在0.2~400μg范围内与峰面积呈线性关系,检出限均为0.1μg·g-1。两种物质的加标回收率在88.4%~95.3%之间,相对标准偏差(n=6)在2.4%~3.5%之间。     

萃取分离-离子色谱法测定间羟基-N,N-二乙基苯胺中的无机阴离子

建立了检测常用化工原料间羟基-N,N-二乙基苯胺中无机阴离子(F-、Cl-、NO3-和SO42-)含量的萃取分离-离子色谱分析方法。方法以甲苯为溶剂溶解间羟基-N,N-二乙基苯胺,用水相萃取分离得到其中的无机阴离子F-、Cl-、NO3-和SO42-等;色谱柱采用Metrosep A supp 5型阴离子分离柱,流动相为3.2 mmol/L Na2CO3与1.0 mmol/L NaHCO3的混合液,流速0.7 mL/min。结果表明:F-、Cl-、NO3-和SO42-的线性关系分别为y=1.2036x 1.0703(r=0.9999)、y=1.3999x-0.2531(r=0.9999)、y=2.6612x-0.9482(r=1.0000)、y=1.9337x 0.0719(r=0.9999);平均回收率分别为F-101.6%(RSD 5.92%),Cl-107.6%(RSD 4.82%),NO3-106.9%(RSD 3.08%),SO42-95.17%(RSD 3.32%);检出限分别为:F-0.003 mg/L、Cl-0.005 mg/L、NO3-0.016 mg/L和SO42-0.010 mg/L。该方法简便、快速、灵敏度高,具有较强的实用价值。     

气相色谱法测定用于食品包装的PVC保鲜膜中作为增塑剂加入的二-（2-乙基己基）己二酸酯

聚氯乙烯(PVC)保鲜膜与作为增塑荆加入的二-(2-乙基乙基)己二酸酯(DEHA)一起用环己酮溶解后于溶液中加入无水乙醇使PVC生成沉淀而与DEHA分离,将滤液用无水乙醇定容为100 mL供气相色谱测定.用HP-5毛细管柱(15 m×0.32 mm,0.25um)作为色谱柱,按预定程序从140℃升温至270℃(气化温度),并记录输出色谱信号.用色谱峰的保留时间进行定性分析,用标准曲线进行定量分析.方法的检出限(3S/N)为0.9 mg·L-1,测得方法的回收率在96.8%-101.4%之间,测得结果的相对标准偏差(n=5)为1.1%.     

模拟唾液浸泡塑料玩具溶出的邻苯二甲酸二(乙基己基)酯的固相微萃取-气相色谱法测定

利用新型溶胶 -凝胶富勒烯C60 涂渍的萃取头 ,采用顶空固相微萃取 -气相色谱法 ,研究了用模拟唾液浸泡塑料玩具溶出的邻苯二甲酸二(乙基己基)酯(DEHP)的固相微萃取(SPME)条件 ,并对聚氯乙烯玩具制品的模拟唾液浸泡液中增塑剂进行了分析和测定 ,方法的检出限为1.02μg/L ,实际样品的检出限为10.2×10-6(w) ,相对标准偏差RSD=10.5 %(n=7)。     

固相微萃取-气相色谱联用技术测定水相中的邻苯二甲酸二(2-乙基)己酯

利用顶空固相微萃取与气相色谱联用技术（HS－SPME－GC）以富勒烯聚二甲基硅氧烷（PSO－C60）固定相处制萃取头分析了塑料浸取液中的邻苯二甲酸二（2－乙基）己酯（DEHP），并对萃取温度、离子强度、吸附时间和热解析时间进行了研究。结果显示，该方法的线性范围在5μg/L－500μg/L，检测出了为2．8μg/L，相对标准偏差为4．8％（n=6).     

气相色谱法测定驱蚊功效印刷品中3种功效化合物

建立了气相色谱–氢火焰离子技术测定功效印刷品中3种驱蚊成分的方法。样品用二氯甲烷进行超声提取,邻苯二甲酸二丁酯为内标,利用毛细管色谱柱HP–5(30 m×0.32 mm,0.25μm)分离,保留时间定性,内标法定量。结果表明,3种驱蚊功效物质色谱分离良好,在质量浓度0.1~1.0 mg/L范围内与色谱峰面积呈线性相关。方法定量限(10S/N)为1.25 mg/kg,样品加标回收率为97%~108%,测定结果的相对标准偏差不大于8.1%(n=6)。该方法快速、可靠、准确、简便,适用于驱蚊功效的印刷品中3种驱蚊功效类化合物的分析检测。     

毛细管气相色谱法测定电热蚊香液中的丙炔菊酯

采用HP－1毛细管气相色谱法对电热蚊香液中丙炔菊酯的含量进行了定量分析，其测定结果的相对标准偏差为0．3％，回收率为103．05，具 有操作准确、简便，快速和实用等特点。     

Gas Liquid Chromatographic Determination of Acetaminophen in Blood Plasma

Abstract

An improved procedure for the GLC determination of acetaminophen (N-acetyl-p-aminophenol) in the presence of N-butyryl-p-aminophenol (internal standard) is described. The method is based on the extraction of acetaminophen from plasma with ethyl acetate containing a known amount of N-butyryl-p-aminophenol. Following a clean-up step with a basic buffer solution and neutralization with acid, both compounds are reextracted into ethyl acetate. The ethyl acetate is evaporated to dryness and the residue dissolved in 5 μl of pyridine and 15 μl of acetic anhydride at 42°C. One to 2 μl samples are injected directly into the gas chromatograph. This extraction process does not give rise to troublesome interfering peaks in the chromatogram. In addition, it prevents late-eluting peaks which inhibit efficient processing of samples. The recovery of acetaminophen is approximately 54%, and the limit of quantitation 0.5 μg/ml of plasma. Data are presented to illustrate the practicality of the method for bioavailability evaluation from acetaminophen plasma levels after oral administration of 325 mg of an acetaminophen dosage form.     

毛细管气相色谱法测定蚊香制品中富右旋反式丙稀菊酯和八氯二丙醚

采用毛细管气相色谱法对无烟蚊香中富右旋反式丙稀菊酯和八氯二丙醚含量进行了测定。结果表明,测定上述分析物的线性范围分别为0.01~4 g/L和0.03~3.60 g/L,线性相关系数分别为0.9995和0.9993;平均回收率分别为92.8%~95.6%、93.4%~96.0%。本法快速、简便,准确,可用于蚊香制品生产过程中的质量监测。     

Gas Liquid Chromatographic Determination of Caffeine in Breast Milk and Blood Plasma

Abstract

An improved procedure for the determination of caffeine in the presence of bupivicaine (internal standard) using gas liquid chromatography with nitrogen phosphorous detection is described. The method is based on the extraction of caffeine from plasma with a mixture of chloroform and isopropanol (95:5). The chloroform and isopropanol mixture is evaporated to dryness and the residue dissolved in 500 μl of ethyl acetate. One to 2 μl samples are injected directly into the gas chromatograph. This extraction process doesn't give rise to troublesome interfering peaks in the chromatogram. The recovery of caffeine from plasma and breast milk is approximately 99.7% and 94.1% respectively. The coefficient variation of the assay from plasma and breast milk is 2.90% and 1.18% respectively. The limit of quantitation is 0.05 mcg/ml of plasma or breast milk. Data are presented to illustrate the practicality of the method for bioavailability and pharmacokinetic evaluation of caffeine plasma and breast milk levels after oral administration of 100 mg of caffeine to lactating mothers.     

Liquid Chromatographic Determination of Sulfamonomethoxine, Sulfadimethoxine, and their N 4-Acetyl Metabolites in Chicken Plasma

An environmentally-friendly method has been established for simultaneous determination of sulfamonomethoxine, sulfadimethoxine, and their N⁴-acetyl metabolites in chicken plasma. The sample is prepared by mixing with 4 mol L^–1 ammonium sulfate solution then centrifugation, and analysis is performed by high-performance liquid chromatography (HPLC) on a polyethylene glycol reversed-phase column with 0.001 mol L^–1 sodium acetate solution as mobile phase and photodiode-array detection. Average recoveries from samples spiked with 0.1, 0.5, and 1.0 g mL^–1 of each drug were >78% and relative standard deviations were within 4%. The practical quantitation limits were 0.09 g mL^–1. No organic solvents or hazardous reagents were used at any stage of the analysis.     

Gas Chromatographic Determination of Cinoxacin

A gas Chromatographic method has been established for analysis of Cinoxacin in crystalline powder. The method is based on chemicaI derivatization of Cinoxacin as its methyl ester, and n-octacosane is used as an internal standard. Gas chromatographic analysis was proceeded on a glass column packed with 2% OV-1 on Chromosorb W. Quantitation is feasible by measurements of peak area ratios. The method proves to be simple, rapid and accurate.     

High-Performance Liquid Chromatographic Determination of Progesterone

Abstract

A practical, rapid, reliable and isocratic reversed-phase HPLC method is described for the determination of progesterone; a method important for determining in cows (1) early pregnancy, (2) reproductive disorders, and (3) timing of artificial insemination. The method is reproducible with a detection limit of 0.5 ng/peak (400 pg/μl) at 254 nm (0.005 AUFS); down by nearly 10-fold from other methods and using simple 254 nm detection. Radioimmunoassay of all eluting fractions demonstrated specificity.     

Gas Chromatographic Determination of Sodium N,N-dialkyl Dithiocarbamates such as their S-n-propyl Esters in Industrial Wastewater

Abstract

A gas chromatographic method for the determination of N,N-dialkyl dithiocarbamates in industrial wastewater at the nanogram level is described. The sample is freeze-dried, extracted with ethanol and then esterified with 1-iodopropane. The method is sensitive, specific, and free from interference of metals. The sensitivity of the method is in the order of 1 ng (injected).