Simple Analysis of Amphetamines in Human Whole Blood and Urine by Headspace Capillary Gas Chromatography with Large Volume Injection

Summary A very simple method for the analysis of methamphetamine and amphetamine in human whole blood and urine by headspace gas chromatography (GC) has been presented. It neither needs solid-phase microextraction nor cryogenic trapping devices, but only a conventional capillary GC instrument with flame ionization detection (FID). The two special points to be mentioned in this method are the in-matrix derivatization of amphetamines for vaporization and the capability of injection of as large as 5 mL of the headspace vapor into a GC instrument in the splitless mode for sensitive detection. After heating a whole blood or urine sample containing amphetamines, -methylbenzylamine (internal standard, IS) and heptafluoro-n-butyryl chloride under alkaline conditions in a 7.0-mL vial at 90 °C for 20 min, 5 mL of the headspace vapor was drawn with a glass syringe and injected into the gas chromatograph. During injection the column was at 40 °C to trap the analytes, and then the oven temperature was programmed up to 320 °C. Sharp peaks were obtained for each analyte and IS, and only a relatively small number of background impurity peaks for the whole blood and urine samples. The detection limits for each amphetamine were estimated to be 0.1 g mL^–1 for whole blood and 0.03 g mL^–1 for urine. Precision and linearity were also tested to confirm the reliability. Methamphetamine and amphetamine could be determined from whole blood and urine obtained at autopsy in three methamphetamine poisoning cases. The identity of each peak appearing in the gas chromatograms was confirmed by GC/mass spectrometry.     

高效液相色谱法测定环境水中超痕量双酚A

合成单分散双酚A(BPA)分子印迹微球并以其为高效液相色谱柱填充材料,建立了一种大体积直接进样HPLC法测定环境水中超痕量BPA的方法。方法的检出限(LOD)和测定限(LOQ)分别为0.03nmol/L和0.1nmol/L;在0.1~100nmol/L范围内具有良好的线性(r2=0.9983)。本方法用于表层湖水中BPA的检测,实际样品的加标回收率在99%~101.4%间;相对标准偏差(RSD%)低于8.1%(n=5)。     

大体积进样离子色谱法测定环境水样中高氯酸根

采用大体积500μL进样离子色谱法,电导检测测定了几种水体中高氯酸盐的含量。分析柱为容量高、亲水性强的以脂肪族碳骨架为基质的阴离子交换柱IonPac AS20,淋洗液在线发生器自动产生35 mmol/LKOH淋洗液,0.25 mL/m in等浓度淋洗。这种新型的以脂肪族碳骨架为基质的阴离子交换柱的采用,极大的削弱了该色谱柱对对氯苯磺酸的保留,完全消除了现行美国EPA高氯酸盐分析方法中高氯酸根与对氯苯磺酸共淋洗的问题。方法对高氯酸根的检出限(S/N=3)为0.5μg/L,高氯酸根浓度在1~1000μg/L范围内具有良好的线性(r=0.9991)。将本方法应用于自来水、河水和雪水样品中高氯酸盐的检测,实际样品的加标回收率在87%~114%之间;1μg/L高氯酸根连续进样9次,色谱峰面积相对标准偏差(RSD)为6.9%。     

大体积直接进样离子色谱法测定饮用水中痕量溴酸盐

建立了一种无需样品前处理,直接大体积进样,电导检测饮用水中痕量溴酸盐的离子色谱新方法。分析柱为容量高、亲水性强的Dionex IonPac AS19阴离子交换柱,EG40在线产生KOH淋洗液,等浓度泵作梯度淋洗。该方法对溴酸盐的检出限为0．2μg／L;在1～100μg/L范围内具有良好的线性（r=0．9996）。将该方法用于北京市自来水和市售瓶装水样品中痕量溴酸盐的检测,实际样品的加标回收率在90％～106％之间;1μg／L溴酸盐连续进样10次,相对标准偏差（RSD）为5．7％。     

Determination of Pollutant Phenols by Capillary High‐Performance Liquid Chromatography with UV Detection

This paper describes a liquid chromatographic method using a reversed phase capillary column coupled to an UV detector for the quantitation of thirteen pollutant phenols. Chromatographic separation was carried out with gradient elution at 25.0 ± 0.1°C. The two major anisocratic elution modes (gradient elution and temperature programming) were evaluated. The detection limit range was 10–81 pg (100 nL injected). The chromatographic method combined with liquid‐liquid extraction was applied to analysis of these compounds in river water. Recoveries of 75–103% were achieved for most of them.     

High Temperature Gas Chromatography with a Glass Capillary Column for the Analysis of High Molecular Weight Tracers in Smoke Samples from Biomass Burning

A custom-made glass capillary column coated with OV-1701-OH (88% methyl, 7% cyanopropyl, 5% phenylpolysiloxane) was used to analyze smoke samples from biomass combustion of different species of plants collected in the Amazon forest. CS₂ was used as solvent in order to enhance the dissolution and analysis of the heavier molecular weight components. The performance of the column was monitored during the experiments and a moderate increase in activity was observed after taking the column to high analytical temperatures (390°C). Trennzahl values typically dropped 20–30% from 1.7/m to the average of 1.35/m. In general, the performance of the custom-made column was satisfactory and comparable to the commercial high temperature columns. The high temperature high resolution GC and GC-MS analyses revealed the presence of a number of high molecular weight components reported to occur in smoke aerosols for the first time. These components consisted of series of wax esters (long chain alcohols esterified with long chain fatty acids) with up to 58 carbon numbers, aliphatic hydrocarbons, triglycerides, triterpenyl esters (e.g. α- and β-amyryl stearate). Although other types of compounds were also detected, their complete structure elucidation solely by electron impact MS was not adequate and other techniques will be required.     

大体积进样离子色谱法检测饮用水中六价铬

建立了离子色谱检测饮用水中的六价铬的分析方法。以AS23柱分离,20mmol／L NaOH为淋洗液,1．0mL／min流量,1mL大体积进样,电导检测。结果表明,方法检测限为0．8μg／L,水样加标回收率在96．0％-102．0％之间,相对标准偏差为4．09％-1．40％;与标准方法二苯碳酰二肼分光光度法结果比对表明,该法检测限低、操作简便、准确快捷,适用于饮用水中六价铬的检测。     

Solvent Trapping during Large Volume Injection with an Early Vapor Exit,Part 2: Chromatographic Results and Conclusions

Solvent trapping reconcentrates volatile components after injection or on-line transfer of large volumes. When an early vapor exit is used, typically after a 5–10 m × 0.53 mm i.d. uncoated precolumn, the solvent trapping process differs from that described previously. The visual experiments and the conclusions drawn therefrom, as described in a previous paper, are supplemented with chromatographic results. They show that even hexane can be quantitatively analyzed in 250 μl of a pentane solution. Injection of a volume of 250 μl by vaporizer/precolumn solvent splitting was used in the analysis of gasoline in drinking water. Conditions for the transfer of a 1000 μl volume can easily be adjusted through detection of the front end of the flooded zone by a thermocouple mounted on the outer wall of the precolumn.     

Determination of Endocrine Disruptors in Environmental Water Samples by Stir Bar Sorptive Extraction-Liquid Desorption - Large Volume Injection-Gas Chromatography

A method based on stir bar sorptive extraction with liquid desorption combined with gas chromatography and mass spectrometry detection has been developed to determine a group of endocrine disruptors in water samples. Large volume injection was used with a programmed temperature vaporiser injector in gas chromatography to enhance sensitivity. The parameters affecting stir bar sorptive extraction and large volume injection were optimised. The limits of quantification in the full scan mode were between 0.02 and 0.2 g L^–1 and the limits of detection were between 0.005 and 0.02 g L^–1 for river water samples. The reproducibility between days of the method (n=3) for river water samples spiked at 0.2 g L^–1 was below 15%. The performance of the method was checked with several water samples from the sea, and effluent and influent sewage treatment plants. We found 4-tert-octylphenol, benzylbutyl phthalate and bis(2-ethylhexyl) adipate in all the water samples analysed at levels between 0.02–14.04 g L^–1. Diazinon was found in only one effluent wastewater sample at 0.16 g L^–1.Acknowledgements This work was supported by the Ministerio de Ciencia y Tecnologia (projects AMB1999-0875 and PPQ2001-1805-CO3). We would like to thank Dr P. Sandra for kindly providing the stir bars.     

GC Analysis of Organic Acids and Phenols Using On-Line Methylation with Trimethylsulfonium Hydroxide and PTV Solvent Split Large Volume Injection

The combination of on-line methylation using trimethylsulfonium hydroxide with large volume injection of 100 μL was evaluated for the analysis of organic acids and phenols in water. Solvent split injection was applied with complete evaporation of the solvent before analytes were transferred onto the GC column. Despite complete solvent removal, losses were very low compared to conventional splitless injection even for volatile acidic compounds such as propionic acid and phenol. This is explained by intermediate formation of low volatility trimethylsulfonium salts of the analytes which were held in the injector for long evaporation times of up to 10 min, if the evaporation temperature was as low as 10°C. Using a simple liquid/liquid extraction procedure, volatile fatty acids, dicarboxylic acids, benzoic acids and phenols could be detected in 5 mL of water at concentrations of 0.04–0.1 μmol/L with GC/MS in full scan mode. Lactic, pyruvic, and also malonic acids could only be detected at higher levels because of their limited extractability from water as well as their poorer methylation yields. The method provides an easy way to sensitively detect acidic compounds of medium to high volatility in water. It was applied for screening of organic acids and phenols in batch cultures of anaerobic bacteria of which one example is shown.     

Solvent Trapping during Large Volume Injection with an Early Vapor Exit. Part 3: The Main Cause of Volatile Component Loss during Partially Concurrent Evaporation

When 0.53 mm i.d. uncoated precolumns connected to a solvent vapor exit are used for sample introduction with partially concurrent solvent evaporation, substantial losses of volatile solutes are often observed. They were found to be the consequence of solute accumulation at the front end of the flooded zone, which in turn is the result of a strong pressure drop over the flooded zone owing to the formation of plugs of sample liquid. The pressure drop causes significant solvent evaporation at the front, which enriches the solute material there and causes its loss. The use of 0.32 mm i.d. restrictions between the uncoated precolumn and the vapor exit greatly reduced this problem.     

Liquid chromatography with diode array detection and multivariate curve resolution for the selective and sensitive quantification of estrogens in natural waters

Following the green analytical chemistry principles, an efficient strategy involving second-order data provided by liquid chromatography (LC) with diode array detection (DAD) was applied for the simultaneous determination of estriol, 17β-estradiol, 17α-ethinylestradiol and estrone in natural water samples. After a simple pre-concentration step, LC–DAD matrix data were rapidly obtained (in less than 5 min) with a chromatographic system operating isocratically. Applying a second-order calibration algorithm based on multivariate curve resolution with alternating least-squares (MCR-ALS), successful resolution was achieved in the presence of sample constituents that strongly coelute with the analytes. The flexibility of this multivariate model allowed the quantification of the four estrogens in tap, mineral, underground and river water samples. Limits of detection in the range between 3 and 13 ng L⁻¹, and relative prediction errors from 2 to 11% were achieved.