Simultaneous measurement of bupivacaine, etidocaine, lidocaine, meperidine, mepivacaine, and methadone

A gas-liquid chromatographic method for the simultaneous measurement of bupivacaine, etidocaine, lidocaine, meperidine, mepivacaine, and methadone in serum is described. The drugs and the internal standard, prilocaine, are extracted from 1 ml of serum. The procedure involves a two-step extraction and injection of the extract into a gas chromatograph equipped with a 10-ft OV-11 glass column and a nitrogen-phosphorus detector. The temperature gradient program results in a run time of 16 min and retention times for meperidine, prilocaine (internal standard), lidocaine, etidocaine, mepivacaine, methadone, and bupivacaine of 3.8, 5.4, 6.0, 8.7, 11.0, 11.7, and 14.8 min, respectively. Standard curves for all drugs were linear over the 80 to 2,000-ng/ml range and recovery of all components averaged 97 +/- 2% with the lowest detection limit of 10 ng/ml for all drugs except meperidine and methadone, which were 20 ng/ml. The within-day coefficients of variation ranged from 12 to 8% at 500 ng/ml. The day-to-day coefficients of variation of the slope and intercept values ranged from 2 to 0% and 130 to 3%, respectively. Response factors of the nitrogen-specific collector varied with the drug analyzed and resulted in peak area variation at constant offset and attenuation of 30%. This method is intended and adequate for therapeutic monitoring of chronically treated pain patients who are being given various combinations of local anesthetic and/or narcotic agents.     

固相萃取-高效液相色谱法测定水中残留嘧菌酯

目的建立固相萃取-高效液相色谱法分析测定水中残留甲氧丙烯酸酯类抗菌剂嘧菌酯的含量。方法样品经过固相萃取小柱净化富集后,采用Inertsil ODS-3色谱柱,乙腈-水（60∶40）为流动相,在250 nm紫外检测波长下进行高效液相色谱分析。结果嘧菌酯在0.01~1.0 mg.L-1范围内呈现良好线性（r=0.9992）。在低、中、高三个添加水平,嘧菌酯的回收率为91.5%~105.2%,相对标准偏差3.7%~8.2%。结论本法操作简便快速,可作为水中嘧菌酯含量监测的控制方法。     

Gas chromatographic analysis of lidocaine in blood and tissues

A rapid, sensitive, and specific gas chromatographic assay for lidocaine in plasma and blood is reported. The procedure involves a single step extraction of the drug and internal standard, and analysis without derivatization. The method can be modified to include the analysis of lidocaine in tissues.     

顶空气相色谱法测定埃索美拉唑钠中溶剂残留量

目的建立顶空气相色谱法测定埃索美拉唑钠中7种有机溶剂残留量的方法。方法采用DB-624(30 m×530μm,3μm)毛细管柱,经程序升温,氢火焰离子化检测器检测,载气为氮气。结果乙醇、丙酮、异丙醇、乙腈、二氯甲烷、甲基叔丁基醚及甲苯在考察范围内线性关系良好(r≥0.999 0),平均回收率为89.7%～104.6%,检测限分别为1.40、0.39、1.60、1.10、0.74、0.04、0.16 mg.L-1。结论本方法可用于埃索美拉唑钠中残留溶剂的检查。     

The determination of bupivacaine, lignocaine and mepivacaine in human blood

A specific method for the quantitative analysis of bupivacaine, lignocaine and mepivacaine in blood, in clinically occurring concentrations, using gas-liquid chromatography, is described. The extraction procedure yields a recovery of 97·5 (±5)%, and the chromatographic conditions allow concentrations as low as 0·04 μg/ml of local anaesthetic in 2 ml of whole blood to be measured. The method has a standard deviation of 5·4%. No interference is encountered from commonly used premedicant or general anaesthetic drugs.     

Determination of zolpidem and zopiclone in serum by capillary column gas chromatography

A gas chromatographic method using a short, high-resolution capillary column connected to a specific thermoionic detector and requiring a simple and short extraction step without evaporation was developed for the rapid and precise determination of two new hypnotics, zolpidem and zopiclone, in serum at concentrations greater than 5 ng/mL. The assay was linear between 5 and 200 ng/mL, with coefficients of intra- and interassay variation less than 5% for both. The method was validated and then used to analyze zolpidem serum concentrations in nine rabbits after oral administration of 0.5 mg/kg and zopiclone serum concentrations in six patients treated orally with a 7.5-g dose.     

Determination of selected organochlorine pesticides and polychlorinated biphenyls in human serum.

A method is presented that can be used to determine the residue level of certain chlorinated pesticides and polychlorinated biphenyls (as Aroclor 1260) in serum. The method involves the following: (1) extraction of denatured serum with organic solvents; (2) elution of the organic extract through micro-Florisil columns to obtain two fractions; (3) acid treatment of the less polar Florisil fraction and its subsequent elution through deactivated silica gel to obtain two fractions; and (4) analysis of all three fractions using gas-liquid chromatography with electron capture detection. The method produced in vitro recoveries for 10 pesticides spiked in the range of 1-10.7 ppb of 50.4% to 121.6%, and in the range of 4.98-21 ppb, recoveries ranged from 47.7 to 112.6. In vivo "recoveries" of Aroclor 1260 averaged 104.8% and 92.3% for concentration levels of approximately 10 and approximately 30 ppb, respectively. The method could not be compared with the more commonly used hexane extraction technique because of the deleterious effect these extracts had on the gas chromatographic system.     

The capillary gas chromatographic determination of trazodone in biological specimens

A simple and specific method is presented for the capillary gas chromatographic determination of trazodone in postmortem blood and tissues. The drug and trimethobenzamide, which was used as an internal standard, were extracted with 1% isopropanol in n-butyl chloride. Chromatography was accomplished with a short (4-m) methyl silicone capillary column and hydrogen carrier gas. This combination of extraction solvent and chromatographic conditions was demonstrated to be both accurate and precise. Since trazodone is a relatively new drug, additional thin layer and packed column gas chromatographic data is presented to augment the incorporation of trazodone into routine analytical protocols.     

Simultaneous determination of viloxazine,venlafaxine, imipramine,desipramine, sertraline,and amoxapine in whole blood: comparison of two extraction/cleanup procedures for capillary gas chromatography with nitrogen-phosphorus detection

A comparative study for the simultaneous gas chromatographic (GC) resolution and detection of the six antidepressants viloxazine, venlafaxine, imipramine, desipramine, sertraline, and amoxapine in whole blood at concentration levels of 100-2000 ng/mL was developed. Two extraction/cleanup analytical procedures were compared regarding their recovery, precision, sensitivity and matrix purification efficiency. The first procedure consists of the employment of Chem Elut columns (diatomaceous earth) and is based on the principle of liquid-solid absorption extraction that is closely related to conventional liquid-liquid extraction. The second focuses on the use of Bond Elut Certify columns and a mixed SPE, reversed-phase and cation-exchange sorbent, more recently developed for the market. Each procedure required 2.0 mL of whole blood extraction and injection into a capillary GC equipped with a nitrogen-phosphorus detector. Mepivacaine was used as the extraction standard (surrogate), and prazepam was used as the chromatographic standard. No interferences were found, and the time for the chromatographic analysis was 16 min for one sample. Recoveries of the compounds using Chem Elut columns at 500 ng/mL were in the range of 28-74% with intra-assay and interassay precisions of less than 7% and 19%, respectively. Limits of detection (LOD) and quantitation (LOQ) ranged from 39 to 153 ng/mL and from 128 to 504 ng/mL, respectively. Recoveries of the compounds using Bond Elut Certify columns at 500 ng/mL were in the range of 64-86% with intra-assay and interassay precisions of less than 4% and 10%, respectively. LODs and LOQs ranged from 21 to 100 ng/mL and from 70 to 330 ng/mL, respectively. An excellent linearity was observed with both procedures from the LOQs up to 2000 ng/mL. The use of the reversed-phase and cation-exchange sorbent Bond Elut Certify showed advantages compared with Chem Elut columns for the screening of these antidepressants such as higher recoveries, cleaner extracts, better sensitivity, better precision, and less solvent consumption and disposal.     

Capillary Gas Chromatographic (GC) Analysis of Nitroglycerin and Its Denitration Products in Plasma

A convenient, specific, and sensitive capillary gas chromatographic (GC) assay for analyzing nanogram concentrations of nitroglycerin and its dinitro- and mononitrometabolites in plasma has been developed. Using a bonded-phase (DB-1) 30-m, 1-µm-thick film capillary column and a 1-m, 5-µm-thick film precolumn, separation of nitroglycerin and all four partially nitrated metabolites was achieved in less than 15 min. On-column injection, electron capture detection, and isothermal operation at 100°C yielded a linear extraction curve over a 300-ng/ml range without any need to concentrate sample extracts. Using methyl t-butyl ether as extraction solvent and o-chloronitrobenzene as internal standard, recoveries from plasma spiked at levels greater than 10 ng/ml approximated 35% for the 1-monometabolite, 40% for the 2-monometabolite, and greater than 90% for all others. The method was employed in a pharmacokinetic study of nitroglycerin administered intravenously to beagle dogs. Plasma samples were collected at various time points and analyzed.     

GC双内标法同时测定细辛挥发油中5种成分的含量

目的建立毛细管气相色谱法同时测定细辛挥发油中5种主要成分（α-蒎烯、β-蒎烯、1,8-桉叶素、黄樟素和甲基丁香酚）的方法。方法采用挥发油提取器提取挥发油;以胡薄荷酮和间二甲苯为双内标物,用HP-5毛细管柱分离,火焰离子化检测器检测;以保留时间定性,内标法定量。结果在所选择的色谱条件下,上述成分在12 min内获得较好的分离;5种成分与内标物的峰面积比值与其质量浓度有良好的线性关系,r〉0.997 7;样品加标平均回收率为96.7%～99.4%,RSD为1.24%～2.31%。结论本方法简单、快速、准确,可同时测定细辛挥发油中5种成分的含量,为细辛质量控制提供依据。     

静态顶空气相色谱法测定苯磺酸氨氯地平中的溶剂残留量

目的建立静态顶空气相色谱法测定苯磺酸氨氯地平中有机溶剂残留量的方法。方法采用静态顶空气相色谱法。检测器为氢火焰离子化检测器,载气为氮气,柱温为程序升温。采用DB-WAX(30 m×0.32 mm,0.25μm)毛细管色谱柱,以N,N-二甲基甲酰胺为溶剂,检测了苯磺酸氨氯地平中乙酸乙酯、异丙醇及甲苯的含量;采用DB-624(30 m×0.25 mm,1.4μm)毛细管色谱柱,以N-甲基吡咯烷酮为溶剂,检测了苯磺酸氨氯地平中N,N-二甲基乙酰胺的含量。结果乙酸乙酯、异丙醇、甲苯及N,N-二甲基乙酰胺在考察范围内线性关系良好,r为0.997 0～0.999 9,平均回收率为101.8%～103.9%,检测限分别为3.50、6.01、1.90和13.3 mg·L-1。结论本方法操作简单、灵敏、准确、重现性好,可用于实际生产中苯磺酸氨氯地平残留溶剂的检查。     

Gas chromatographic determination of propylene glycol dinitrate in rodent skin.

A gas chromatographic (GC) method was developed for the detection of propylene glycol dinitrate (PGDN) in rodent skin following extraction with ethyl acetate. Known quantities of PGDN contained in the torpedo fuel Otto Fuel II were added to homogenates of rat skin, which were subsequently extracted with two 10-mL portions of ethyl acetate. An aliquot of each extract was analyzed by GC with a flame ionization detector. With this method, concentrations ranging from 0.0042 to 11.2 mg/mL were determined by comparison with a standard curve. The extraction efficiencies ranged from 85.7% for the lowest concentration to 101% for the highest concentration.     

Determination of tetraconazole and diniconazole fungicide residues in tomatoes and green beans by capillary gas chromatography

A sensitive gas chromatographic method using an electron-capture detector (ECD) has been developed for the determination of tetraconazole and diniconazole fungicide residues in tomatoes and green beans. The developed method consists of extraction with methanol, partition with methylene chloride, and column chromatographic clean-up, followed by capillary gas chromatographic determination. The recoveries of both fungicides were greater than 90% for both plant samples. The limits of determination of the method were 0.001 ppm for both fungicides. The method was applied to determine residues and the rate of disappearance of tetraconazole and diniconazole from tomatoes and green beans [open field treatment, 50 cc of Domark 10% EC (emulsifiable concentrate), and 35 cc of Sumi-eight 5% EC; both for 100 l of water]. The fungicides incorporated into the plants decreased rapidly with a half-life around 3 days for diniconazole and from 4.5 to 6.5 days for tetraconazole. No residues could be detected in the plants during the period of study of 21 days after field application. Hence, the plants could be used safely after that period of time.     

反相高效液相色谱法测定人血浆中甲哌卡因的浓度

目的:建立反相高效液相色谱紫外法测定人血浆中甲哌卡因浓度。方法:采用Diamonsil ODS C₁₈分析柱（150 mm×4.6 mm,5μm）,柱温为室温,流动相为甲醇-乙腈-0.03 mol·L^-1KH₂PO₄缓冲液（H₃PO₄调pH为5.3）（50:50:250）,流速:1.0ml·min^-1;0.5 ml血浆样品经固相萃取方法处理后,洗脱液在50℃条件下空气吹干,残渣用流动相溶解进样,紫外检测器检测,检测波长为210 nm。结果:标准曲线在20～4 000 ng·ml^-1范围内线性良好,最低定量限为20 ng·ml^-1,甲哌卡因及内标的保留时间分别为7.5 min和19.4 min,日内和日间RSD均<14.0%,方法提取回收率分别在103.5%～109.2%。结论:本法具有简便、灵敏、准确等优点,成功用于经硬膜外给予200 mg盐酸甲哌卡因患者血浆液中甲哌卡因浓度测定及药动学研究。     

Determination of valproic acid in plasma or serum by solid-phase column extraction and gas-liquid chromatography

A simple, fast, sensitive, and inexpensive method is described for routine therapeutic monitoring of both total and free valproic acid (VPA) at therapeutic concentrations in seizure patients. The method uses solid-phase (Bond Elut) columns for the preliminary extraction of 100 microliters plasma or serum and gas-liquid chromatography (GLC) analysis, using 10% Carbowax 6000 on a Chromosorb WAW 80/100 column and alpha-methyl-alpha-ethylcaproic acid as an internal standard. The extraction efficiency for VPA at a concentration of 70 micrograms/ml is 98 +/- 4%. The calibration curve is linear in the range of 1.0-280 microliters/ml. The detection limit of VPA is 1.0 micrograms/ml. Syva enzyme multiplied immunoassay technique (EMIT) Free-Level filters were used in the analysis of free VPA from plasma. The described Bond Elut X GLC (BE X GLC) method was used to determine total drug concentrations in 56 VPA-treated patients, and the results were compared with those obtained by conventional liquid-liquid extraction X GLC analysis. The 44 sera involved were also analyzed by EMIT. In addition, BE X GLC was compared with the Abbott TDx system on an additional 21 specimens. Statistical agreement was excellent between BE X GLC and TDx, but poor between BE X GLC and liquid-liquid extraction X GLC. Agreement with the EMIT method was intermediate.     

Rapid gas chromatographic profiling and screening of acidic non-steroidal antiinflammatory drugs in biological samples

The solid-phase extraction (SPE) with subsequenttert.-butyldimethylsilyl (TBDMS) derivatization was investigated for the rapid profiling and screening of various carboxylated non-steroidal antiinflammatory drugs (NSAIDs) simultaneously in biological fluid samples. Compared to the conventional SPE in adsorption mode using Chromosorb 102, Chromosorb 107, Carbopak B and Thermosorb, the SPE in partition mode using Chromosorb P as the adsorbent, and ethyl acetate/methylene chloride as the eluting solvents provided highest overall recoveries of the NSAIDs from aqueous solutions with good precision. The solid-phase extracted NSAIDs were silylated with N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide to TBDMS derivatives and directly analyzed by capillary gas chromatography and gas chromatography-mass spectrometry. The usefulness of the present method was examined for the profiling and screening of saliva, serum and urine samples for various NSAIDs simultaneously.     

GLC determination of plasma levels of intact chlorpropamide or tolbutamide.

A GLC procedure was developed for the quantitative estimation of intact chlorpropamide and tolbutamide concentrations in plasma; the drugs are used as mutual internal standards. After extraction of plasma containing the drug and internal standard with toluene, the dried residue is treated with ethereal diazomethane to form the methyl derivatives of tolbutamide and chlorpropamide. Aliquots of the ethereal solution are injected into a gas chromatograph equipped with a glass-lined injection port and glass column packed with a phenyl methyl silicone fluid (OV-25) on Chromosorb W, which facilitates the intact determination of the methyl derivatives of the drugs. The response to the flame-ionization detector was linear over a range of 0.20-25 mug/ml, with a 0.05-mug/ml limit of detectability for both drugs. The method compares favorably with a recently developed high-pressure liquid chromatographic procedure and is adequate for following blood level profiles of single doses of chlorpropamide (125 mg) and tolbutamide (250 mg). Mass spectral evidence showing that intact sulfonylureas are measured is presented.     

Determination of buspirone and 1-(2-pyrimidinyl)-piperazine (1-PP) in human plasma by capillary gas chromatography.

Two separate gas chromatographic methods for the determination of buspirone and its active metabolite, 1-(2-pyrimidinyl)-piperazine (1-PP) in human plasma are described. Both procedures involve solid-phase extraction (the packing material of the cartridges used was C8 for buspirone and a mixed-mode sorbent for 1-PP), injection of the sample into a gas chromatograph equipped with a fused-silica capillary column and a nitrogen-phosphorus detector, and analysis with temperature programming (from 220 degrees C to 285 degrees C for buspirone and from 138 degrees C to 285 degrees C for 1-PP). The coating material of the analytical column was 5% diphenyl dimethyl silicone for buspirone and 50% diphenyl dimethyl silicone for 1-PP. Zolpidem was used as an internal standard in the buspirone assay and 1-phenylpiperazine in the 1-PP assay. Recovery of buspirone and 1-PP averaged 98% and 89%, respectively, and the limit of quantification was 0.2 ng/mL for both compounds. The between-run coefficients of variation ranged from 3.2% to 9.4% and from 2.9% to 8.6% for samples spiked with three different concentrations of buspirone and 1-PP, respectively. The suitability of these assays for pharmacokinetic studies was shown by analyzing timed plasma samples from volunteers after ingestion of a single therapeutic dose of buspirone (10 mg).     

High-performance liquid chromatographic analysis of norfloxacin in human tissues and plasma with fluorescence detection

A high-performance liquid chromatographic analysis with fluorimetric detection is described for the quantitative determination of norfloxacin in renal, prostatic tissues and in plasma. The analytical procedure in the tissue pretreatment, consists of purification of the obtained sample by a solid state extraction and quantitation by HPLC. The samples were chromatographed on a C(8) reversed-phase column. Analytical recoveries ranged from 95.2 to 97.6%. Within and between day precision were assessed by analysing serum containing 50 and 500 ng/ml norfloxacin. At each concentration, within day precision was 3.6% (relative standard deviation, n = 10) and day-to-day precision was 5.3% (n = 10). Limit of detection was ca 1 ng/ml.