液化气中元素硫的高效液相色谱法分析

应用溶剂萃取、冷却气化方法对液化气样品进行前处理。对前处理制备的样品使用高效液相色谱法进行测定,以甲醇／水＝９５／５（Ｖ／Ｖ）为流动相,紫外检测（２５４ｎｍ）,在Ｃ１８柱上成功地分离并测定了元素硫的含量。方法检测限为０．１ｎｇ／ｇ,有良好的准确度与精密度,能充分满足各种液化气中元素硫的测定需要。     

Tocainide Determination by High-Performance Liquid Chromatography

Abstract

Tocainide has been assayed after serum deproteinization with acetonitrile by HPLC. The pH was critical in separating the drug from other interferences in the serum. The method is simple and fast.     

Determination of Squalene Using High-Performance Liquid Chromatography with Diode Array Detection

A high-performance liquid chromatographic method with photodiode array detection has been developed for the determination of squalene. After treated by extraction and fractional crystallization, squalene was analyzed on a C₁₈ column (150 × 3.9 mm, 5 m) with acetonitrile as mobile phase. Excellent linearity of the calibration curve was observed in the range of 100–40000 gL^–1 and the detection limit was 40 gL^–1. The recoveries were from 89.6% to 100.5% and the relative standard deviations were from 0.5% to 1.4%. The method was successfully applied to the determination of squalene in squalene capsules, olive oil, algal lipids and algal cells.     

Determination of Reserpine in Plasma Using High-Performance Liquid Chromatography with Fluorescence Detection

Abstract

A high-performance liquid chromatographic method for determining reserpine in plasma has been developed. The procedure involves extraction of reserpine from buffered plasma into benzene, oxidation of reserpine to a fluorophor by treatment with vanadium pentoxide in phosphoric acid, and chromatographic separation of the reserpine fluorophor on an octadecylsilane column by ion-pairing with heptanesulfonate ions. Fluorescence monitoring of the column effluent provides high sensitivity of detection and increases the specificity of the procedure. A detection limit of approximately 100 pg of reserpine per ml of plasma was obtained following analysis of 2 ml samples. Analysis of a number of samples demonstrated the applicability of this method in confirming the presence of reserpine in equine plasma specimens collected at various horse shows and in evaluating the pharmacokinetic behavior of reserpine following intramuscular administration to horses.     

Rapid Determination of Apomorphine in Brain and Plasma Using High-Performance Liquid Chromatography

Abstract

A new method for quantitative determination of apomorphine in mouse brain and rat plasma is described. The drug was extracted utilizing SEP-PAK C₁₈ cartridge, and quantified by high performance liquid chromatography with electrochemical detector. The average recovery was 92 ± 2.8% with a day-to-day coefficient of variation of 10.2%. Apomorphine concentration in mouse brain and in rat plasma, as a function of dose and time, after injection with apomorphine-HCl were determined. The results indicate that the method is adequate for pharmacokinetic studies.     

Micro-Scale Method for Determination of Tobramycin in Serum Using High-Performance Liquid Chromatography

Abstract

A rapid, simple, accurate, and micro-scale method for the determination of tobramycin, sisomicin and netilmicin in serum using high-performance liquid chromatography has been developed. The method is sensitive to 0.3 pg/ml using only 20 μl of serum. The serum is deproteinized with methanol containing an internal standard: sisomicin for the tobramycin, netilmicin for the sisomicin, and sisomicin for the netilmicin. After centrifugation, a counter-ion reagent is added to the supernatant, then an aliquot of the solution is injected into the chromatograph. Tobramycin, sisomicin and netilmicin are separated by reversed-phase, ion-pair chromatography and detected by fluorescence using continuous-flow, post-column derivatization with o-phthalaldehyde. For the tobramycin, within-run and day-to-day variation was below 2.5%. Correlation of this method with microbiological assay and homogeneous enzyme immunoassay was good.     

Determination of Monobromobimane-Labeled Phytochelatins by High-Performance Liquid Chromatography

A new method for phytochelatins by high-performance liquid chromatography (HPLC) was developed based on a condensation reaction with monobromobimane to produce fluorescent derivatives. Glutathione, H-(γ-glutamic acid-cysteine)₂-glycine-OH, H-(γ-glutamic acid-cysteine)₃-glycine-OH, H-(γ-glutamic acid-cysteine)₄-glycine-OH, H-(γ-glutamic acid-cysteine)₅-glycine-OH, and H-(γ-glutamic acid-cysteine)₆-glycine-OH were well separated, with retention times between 14.68 and 22.0 min. The HPLC method had good linearity (r < 0.9991) between 0.1 mg L^?1 and 100 mg L^?1. The limits of quantification for the analytes (S/N = 3) were 0.08, 0.3, 0.05, 0.3, 0.5, and 0.8 mg L^?1, respectively. The recoveries were between 83.0% and 101.33% with relative standard deviations less than 2%. The reported method is simple, accurate, and suitable for the determination of phytochelatins.     

高效液相色谱法测定环己铜过氧化物

以甲醇或甲醇与水作流动相,ODS为固定相,测定环己酮的多种过氧化物。平均回收率100.2％～101.6％,测定的相对标准偏差为1.02％～2.51％。     

Determination of Carbonyl Compounds by High-Performance Liquid Chromatography

Carbonyl compounds in the form of 2,4-dinitrophenylhydrazones in alcoholic solutions were analyzed by high-performance liquid chromatography. This simple procedure is characterized by high sensitivity and reproducibility.     

Quantitation of Baclofen in Tablets Using High-Performance Liquid Chromatography

Abstract

A reverse phase high-performance liquid chromatography method has been developed to quantify baclofen in tablets. The method is accurate and precise with a percent relative standard deviation of 0.52 based on 5 readings. The recovery from the synthetic mixtures was quantitative. The results were in excellent agreement with the USP-NF colorimetric method. The method can be used to test the content uniformity of the tablets. Samples which were treated with either sulfuric acid or sodium hydroxide and boiled for 10 minutes did not show new peaks in the chromatogram. Baclofen appears to be a very stable compound.     

Determination of Acyclovir in Human Serum by High-Performance Liquid Chromatography

Abstract

A method was developed for determination of concentrations of acyclovir in serum. Serum proteins were precipitated with equal part of 5% perchloric acid. High-performance liquid chromatography was used for separation from endogenous compounds and detection was done with spectrophotometry. The assay is simple and precise and seems well suited for pharmacokinetic studies.     

Determination of Cefpirome in Human Plasma by High-Performance Liquid Chromatography

Abstract

Cefpirome is an investigational third-generation cephalosporin, which appears promising for the treatment of various pediatric infections. A high performance liquid chromatographic method was developed to measure cefpirome in small volumes of plasma for conducting pharmacokinetics studies in infants and children. the assay involved precipitation of plasma proteins with acetonitrile, using cefaclor as an internal standard. Chromatographic separation was accomplished using a reverse-phase     

高效液相色谱法测定血清中茶碱浓度

采用高效液相色谱,分析柱：３μｍ,３．３ｃｍ＊４．６ｍｍ,Ｉ．Ｄ（Ｐｅｒｋｉｎ Ｅｌｍｅｒ,ＵＳＡ）;预柱：１０μｍ,１ｃｍ＊２．１ｍｍ,Ｉ．Ｄ（Ｐｅｒｋｉｎ ＥＬｍｅｒ,ＵＳＡ）;以乙酰氨基酚为内标对氯仿－异丙醇（９５：５,Ｖ／Ｖ）提取样品进行了分析,流动相：０．１ｍｏｌ／Ｌ醋酸缓冲液（ＰＨ＝４．５）－甲醇（７０：３０,Ｖ／Ｖ）;检测波长：２７０ｎｍ;流速０．５ｍＬ／ｍｉｎ,３ｍｉｎ即完成一次茶     

Determination of Pyridostigmine in Human Plasma by High-Performance Liquid Chromatography

Abstract

An easy to perform, specific, reproducible and sensitive high performance liquid chromatographic (HPLC) method to measure pyridostigmine concentration in human plasma was developed and validated. Sample clean-up consists of ion-pair extraction into dichloromethane in the presence of neostigmine as internal standard, followed by back extraction into an aqueous phase. Mean recovery of 110% (with a standard deviation of 10%) was determined for concentrations of 5 – 100 ng/ml. Chromatography on a 125·4 mm CN-propyl column using a mobile phase composed of 10% acetonitrile in 3.5×10^?4M NaH₂PO₄ and UV detection at 270 nm, yields clean chromatograms without any interferences from endogenous plasma components. Using 1 ml plasma samples the method has a limit of detection (LD) of 3 ng/ml, with %CV (precision) and bias (accuracy) ≥ 10% for concentrations in the range of 0–100 ng/ml. The method is being used in human pharmacokinetic studies of oral dosage forms of pyridostigmine.     

Simultaneous Determination of Food-Related Amines by High-Performance Liquid Chromatography

Abstract

Ten amines found in marine foods, dimethylamine, trimethylamine, trimethylamine oxide, ammonia, urea, histamine, cadaverine, putrescine, spermine and spermidine were separated by HPLC using an ion-moderated partition column. Optimum resolution and sensitivity were obtained using 0.003N sodium hydroxide as the mobile phase and UV detection at 208 nm.     

Quantification of Leukotriene B4 Using High-Performance Liquid Chromatography

Abstract

Leukotriene B₄ (LTB₄) was derivatized with p-(9-anthroyloxy) phenyl bromide forming the panacyl ester. The yield from this reaction was 95 percent. Subsequent separation of this ester using reversed phase high-performance liquid chromatography resulted in a greater than 10 fold increase in sensitivity as measured directly with ultraviolet light (absorption at 254 nm). Sensitivity was 16 ng and elution time was less than 15 minutes. We applied this technique to quantification of LTB₄ production by human polymorphonuclear leucocytes.     

高效液相色谱法测定有机肥中洛克沙胂

建立了高效液相色谱(HPLC)-串联紫外检测法检测有机肥中洛克沙胂的分析方法。选用20g·L-1K2HPO4作为提取剂,于60℃温度下超声提取有机肥中的洛克沙胂,采用MAX固相萃取柱净化。结果表明,采用Symmetry ShieldTMRP 18色谱柱,以含0.1%甲酸的0.05mol·L-1 KH2PO4∶甲醇=95∶5(V/V)溶液作流动相,等度洗脱,紫外266nm检测,洛克沙胂的保留时间短,且可完全避开杂质峰的干扰;其平均加标回收率介于81.14%~82.75%之间,相对标准偏差(RSD)7.0%,检出限为20μg·L-1。方法重现性好,精密度高,操作简便,适用于有机肥中洛克沙胂检测。     

高效液相色谱法测定肉制品中甘草抗氧化物的含量

建立了测定肉制品中甘草抗氧化物含量的方法。样品经流动相提取,采用C．8色谱柱分离,以甲醇-0．2mol／L乙酸铵-冰乙酸（体积比70：29：1）为流动相,流速为1．0mL／min,波长为250nm,以保留时间进行定性,峰面积进行定量。甘草酸在1．0-80．0μg／mL范围内线性关系良好,回归方程为y=8．55×10^-5x-0．599（r=0．9997）,检出限为1．0mg／kg,定量限为3．0mg／kg,加标回收率为95．7％-103．4％,测定结果的相对标准偏差为1．57％-3．53％（n=6）。该方法适用于检验机构日常检验中大批量肉制品中甘草抗氧化物含量的测定。     

Determination of Nimesulide by Ion Pair High-Performance Liquid Chromatography Using Tetrabutylammonium as the Counterion

A new method for nimesulide was developed using ion-pair reversed phase liquid chromatography and tetrabutylammonium hydrogen sulfate as the ion-pairing reagent. The influence of the ion pair forming reagent concentration, pH, and mobile phase composition on the retention time of nimesulide were studied. The optimum experimental conditions included a C18 column, a mobile phase of a 50/50 (v/v) mixture of acetonitrile and 15 mM phosphate buffer (pH 8.00) containing 6 mM tetrabutylammonium hydrogen sulfate, 25°C, isocratic elution, a flow rate of 1 mL/min, a run time of 10 minutes, and photodiode array detection at 404 nm. From the analysis of the results, the mechanism for the separation of nimesulide was also established. The retention time for nimesulide was 4.76 ± 0.05 min. The method was linear between concentrations of 9 µg/mL to 64 µg/mL, with limits of detection and quantification of 1.111 µg/mL and 3.390 µg/mL, respectively. The method is simple, rapid, accurate, and precise, and successfully applied for the determination of nimesulide in pharmaceutical products.     

Rapid and Sensitive Method for Citrinin Determination Using High-Performance Liquid Chromatography with Fluorescence Detection

Citrinin is a toxic product of secondary metabolism of fungi, such as certain Aspergillus, Penicillium, and Monascus species that are usually contaminating cereals. A new sensitive liquid chromatographic method with fluorescence detection was developed, validated, and applied for citrinin determination. The method is based on reversed-phase separation at pH 2.5, where citrinin exhibits the highest fluorescence quantum yield. In this setup, no derivatization step is needed. The method shows linearity in the range between 0.2 μg/mL and 0.1 mg/mL. The detection limit reached is 90 ng/mL (3.6 × 10^?7 M). Validated method was successfully applied on analysis of spiked and real cereal samples.