Determination of Diclofenac Sodium in Synovial Fluid by High Performance Liquid Chromatography

Abstract

Due to the limited supply of blank synovial fluid, the usual practice of preparing a calibration curve for the biological sample of measurement is not practical for synovial fluid drug level determination. The linearity and correlation of peak height ratio between plasma and synovial fluid samples were investigated in this study. Excellent linear relationship is obtained from the calibration curves for both biological samples. In addition, excellent correlation of peak height ratios between plasma and synovial fluid indicates that the plasma calibration curve can be used in lieu of a synovial fluid calibration curve (slope 0.9154; intercept not statistically different than zero; and r-0.999 with N=13). According to this linear relationship, synovial fluid levels can be calculated based on the concentration as determined from the plasma calibration curve and divided by 0.9154. The extraction efficiences were comparable when diclofenac was spiked into human plasma or synovial fluid samples but the extraction of internal standard is better from synovial fluid than from plasma. The results are in good agreement with those observed in correlation between plasma and synovial fluid. Linearity and sensitivity of diclofenac in synovial fluid were determined in this study, but precision, accuracy and specificity were not determined due to the difficulty to obtain blank synovial fluid. Nevertheless, the same assay has been applied to plasma where all parameters have been well established and it is reasonable to assume the same results would have been obtained from synovial fluid samples.     

Rapid Simultaneous Determination For Catecholamines By Reversed-Phase High-Performance Liquid Chromatography

Abstract

An improved reversed-phase high performance liquid chromatographic technique for the rapid simultaneous analysis of patecnolamines is presented.

The catecholamines are preconcentrated by employing a single preconcentration step, solid-liquid extraction, with active alumina.

A C₁₈ reversed-phase column is used and the catecholamines are detected at 280 nm. the retention time is 3.7 min for norepinophrine, 4.5 min for epinephrine and 6.2 min for dopamine using an eluting system of 0.165 M AcOH 1 pc in MeOH.

The within-run precision CVs are in the order of 7 pc whereas the day-to-day precision CVs are in the order of 10 pc for concentrations near the upper normal limits. the application of the technique to a series of hypertensive subjects indicated, after comparison with three patients with than sixfold of upper normal limits in addition to fourfold or more increase in DA excretion seems to be indicative for the presence of malignant pheochfomocytoma. to assess the efficiency of such a discriminating criterion a larger number of cases of pheochromocytoma and essential hypertension have to be studied. In conclusion, we propose a rapid, precise and low-cost HPLC technique for the determination of urinary catecholamines requiring only one pump and a UV-detector. the technique may prove useful in hospitals as a tool in discriminating between essential hypertention and pheochromocytoma.     

A Rapid Isocratic Reversed-Phase Separation and Determination of Some Barbiturates by High-Performance Liquid Chromatography

Abstract

A high performance liquid chromatographic method for the rapid separation and quantitative determination of five barbiturates in pharmaceutical preparations and body fluids has been developed. A C₁₈ reversed phase column was used and the barbiturates were detected at 235nm.

A number of eluting systems were examined, the most suitable of them being, Ethanol:Propanol:Methanol:Water (26:5:29:40) at pH = 8.8.     

Rapid Analysis for Codeine by Reversed-Phase High-Performance Liquid Chromatography

Abstract

A reversed phase high-performance liquid chromatographic (HPLC) method has been established for the separation and quantitative determination of the alkaloid codeine in pharmaceutical preparations and in body fluids. The minimum detectable concentrations for body fluids were 5ppb and 7ppb respectively for urine and whole blood with an analysis time of under 5 min. A RP-8 Spheri-5 guard column and a RP-8 Lichrosorb-10 column were used and codeine was detected at its absorption maximum wavelength of 212 nm using an eluting system of methanol: 0.5% w/v aqueous ammonium acetate (70:30) at a pH of about 7.0.     

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.     

液相色谱法快速测定化妆品中抗氧化剂

本文提出了一种应用高效液相色谱法同时测定化妆品中三种常用抗氧化剂的快速方法。应用微量化学法技术处理样品，提高了分析速度。样品用乙腈提取，提取液过Ｃ１８微柱净化。净化液在反相色谱柱上进行测定，检测波长２８０ｎｍ，流动相为２０％乙腈水溶注，１０ｍｉｎ内线性梯度变为１００％乙腈，乙腈水均各加５％醋酸。     

Microdetermination of Bile Acids by High-Performance Liquid Chromatography Equipped with a High Sensitive Conductance Detector

Abstract

Conductimetric detection of bile acids in reversed phase high-performance liquid chromatography is described. The solvent system of the mixture of water and organic solvent containing small amount of basic salts such as ammonium carbonate is found useable by removing the cation with the cation exchange column inserted between the ODS column and the conductance detector. Thus, a few ng of tauro-and glyco-conjugated bile acids can be detected without tedious derivatization and hydrolysis.     

用亲水性的C16硅胶反相色谱柱分离测定血清样品中的雌激素

将亲水性较强的C16硅胶反相色谱柱应用于血清样品中β-雌二醇、雌三醇、雌酮和17α-乙炔基雌二醇的分离。实验对分离条件进行了优化,得到的最佳色谱条件是：柱温40℃,流速1mL／min,以40％乙腈水溶液作等度洗脱。在此条件下．4种雌激素可在大约26min内实现基线分离,得到的4个色谱峰峰型对称。分离后的4种雌激素用紫外检测器在200nm处进行测定,方法对β-雌二醇、雌三醇、雌酮和17α-乙炔基雌二醇的检出限分别为0．024、0．015、0．012和0．016mg/L;校正曲线的线性范围为2-3个数量级,相关系数为0．998以上。方法应用于血清样品的测定,β-雌二醇、雌三醇、雌酮和17α-乙炔基雌二醇的标准加入回收率分别为96．3％、103．7％、100．1％和95．2％。     

Determination of Tetracyclines in Milk by Graphene-Based Solid-Phase Extraction and High-Performance Liquid Chromatography

A graphene-based solid-phase extraction (SPE) column was prepared for the isolation of tetracyclines from milk followed by determination by high-performance liquid chromatography. Graphene provided better separation for tetracyclines than amine-modified graphene and carboxyl-modified graphene. The optimized graphene-based SPE column showed high absorption capacities (greater than 4,660?ng) and high recoveries (exceeding 92%) for tetracycline, oxytetracycline, chlortetracycline, and doxycycline and was successfully reused at least fifty times. The limits of detection in milk were from 10 to 20?ng/mL, with recoveries between 82.3 and 103.6%. Furthermore, the system showed superior performance than two commercial SPE cartridges with respect to recovery, purification, and reusability. Therefore, this approach is suitable for the determination of tetracyclines in milk.     

Development of Improved High-Performance Liquid Chromatography Method for the Determination of Residual Caprylic Acid in Formulations of Human Immunoglobulins

Quality control of human immunoglobulin formulations produced by caprylic acid precipitation necessitates a simple, rapid, and accurate method for determination of residual caprylic acid. A high-performance liquid chromatography method for that purpose was developed and validated. The method involves depletion of immunoglobulins, the major interfering components that produce high background noise, by precipitation with acetonitrile (1:1, v/v). Chromatographic analysis of caprylic acid, preserved in supernatant with no loss, was performed using a reverse-phase C18 column (2.1 × 150 mm, 3 μm) as a stationary phase and water with 0.05% TFA–acetonitrile (50:50, v/v) as a mobile phase at a flow rate of 0.2 mL/min and run time of 10 min. The developed method was successfully validated according to the ICH guidelines. The validation parameters confirmed that method was linear, accurate, precise, specific, and able to provide excellent separation of peaks corresponding to caprylic acid and the fraction of remaining immunoglobulins. Furthermore, a 2⁴⁻¹ fractional factorial design was applied in order to test the robustness of developed method. As such, the method is highly suitable for the quantification of residual caprylic acid in formulations of human immunoglobulins for therapeutic use, as demonstrated on samples produced by fractionation of convalescent anti-SARS-CoV-2 human plasma at a laboratory scale. The obtained results confirmed that the method is convenient for routine quality control.     

高效液相色谱法快速测定冰淇淋中的糖精钠

用高效液相色谱法快速测定了冰淇淋中的糖精钠。使用反相径向加压柱,紫外检测定量。样品用硫酸铜及氢氧化钠处理后,滤液不用萃取即可上机检测。方法的最低检测限为0．38mg／kg,变异系数为1．72％,回收率为96．25％。     

Determination of Pharmaceuticals by Dynamic Cell Membrane Chromatography Coupled with High-Performance Liquid Chromatography

As a biological affinity chromatographic method, cell membrane chromatography (CMC) using a silica stationary phase covered with specific cell membrane has been used in screening active components. The innovation of this work is that the bioactive cell membrane and the chromatographic packing are mixed and absorbed for the first time to form the pre-column. The pre-column was placed in front of a C₁₈ column to create dynamic CMC online high-performance liquid chromatography (HPLC) system. The retention behavior and dynamic changes of pharmaceuticals were studied for this system. The results indicate that the retention time of the drug was increased and the symmetry factor reached the analytical level after the addition of the dynamic cell membrane pre-column. Therefore, the dynamic CMC coupled with HPLC system may be a potentially rapid and efficient drug analysis approach for the interaction of drug molecule and receptor on red blood cell membranes.     

High-Performance Liquid Chromatographic Determination of Isofraxidin in Rat Plasma

For the first time a high-performance liquid chromatographic (HPLC) method, with liquid-liquid extraction and ultraviolet (UV) absorbance detection, has been developed for quantification of isofraxidin in rat plasma. The analysis was performed on a Diamonsil C₁₈ column (200 mm × 4.6 mm i.d., 5 μm particle size) with acetonitrile–0.05% phosphoric acid, 26:74 (v/v), as isocratic mobile phase. The linear range was 0.05–8.0 μg mL⁻¹ and the lower limit of quantification was 0.05 μg mL⁻¹. The intra and inter-day relative standard deviation (RSD) for measurement of 0.25, 2.0, and 6.0 μg mL⁻¹ quality-control (QC) samples ranged from 5.7 to 6.4% and from 6.3 to 7.9%, respectively. Accuracy, as relative error (RE), was from ±5.8% to ±7.3%. The method was validated for specificity, accuracy, and precision and was successfully used in a pharmacokinetic study of isofraxidin in rat plasma after administration of Ciwujia extract.     

高效液相色谱法测定血浆中莲心碱的浓度

采用高效液相色谱法（甲基莲心碱为内标）测定了血浆中莲心碱的浓度。以ＵｌｔｒａｓｐｈｅｒｅＳｉ为固定相、二氯甲烷－异丙醇－二乙胺（７５１５０．２,Ｖ／Ｖ）为流动相,检测波长为２８２ｎｍ。血样用氨－氯化铵缓冲液调ｐＨ１０后用乙醚提取。平均回收率９３．６％,ＲＳＤ为１．９％,最低检测浓度０．０２５ｍｇ／Ｌ。     

高效液相色谱法测定舒普深中的舒巴坦钠和头孢哌酮钠

 应用反相高效液相色谱外标定量法同时测定了舒普深中的舒巴坦钠和头孢哌酮钠。采用 pH 4 0的磷酸水溶液 乙腈 (体积比为 80∶2 0 )组成的流动相 ,在ODS柱上 ,于 12min内同时测定舒巴坦钠和头孢哌酮钠。方法简单 ,重现性好 ,在线性范围内舒巴坦钠的相关系数为 0 9997(n =5 ) ,头孢哌酮钠的相关系数为 0 9991(n=5 )。方法适于对药品舒普深的生产过程及临床上该药的血药浓度的监测。     

Determination of Simazine and Atrazine in River Water by Cloud-Point Extraction and High-Performance Liquid Chromatography

Atrazine and simazine are endocrine-disrupting herbicides that may be transported to surface water, unbalancing ecosystems. Sensitive and low-cost methods are required for monitoring the residues of these compounds. Although several highly sensitive chromatographic methods coupled to tandem mass spectrometry are available, these methods use high-cost instrumentation. Ultraviolet detection usually does not provide the sensitivity and selectivity for monitoring these herbicide residues at the maximum concentrations levels permitted by regulatory agencies, so that extraction and concentration steps are required. Cloud-point extraction in Triton X-114 micelles was investigated to extract and preconcentrate atrazine and simazine. Treatment of 10?mL of sample solutions with 5?mL of 5% (m v^?1) Triton X-114 in the presence of NaCl (0.3?g) with heating at 60°C for 30?min led to phase separation and the transfer of herbicides to the surfactant-rich phase, which was dissolved in 90:10 methanol:water for liquid chromatography analysis with ultraviolet detection. The linear dynamic range was 1–50?µg?L^?1 for the herbicides. The limits of detection were 0.13 and 0.27?µg?L^?1 for simazine and atrazine, respectively. The methodology was applied to water samples fortified with 1, 5, 15, and 50?µg?L^?1 of the analytes, resulting in recoveries between 86 and 132% with relative standard deviations less than 6%. The method is low cost and uses small volumes of toxic solvents with useful application in trial studies.     

Microdetermination of Heavy Metal Chelates by High-Performance Liquid Chromatography

Abstract

Adsorption chromatography of diethyldithiocarbamate chelates of heavy metals is described. Determination of heavy metals including Hg (II), Cd (II), Pb (II), Cr (VI), Bi (III) and Cu (II) in micro to nano gram order is successfully carried out with good accuracy and reproducibility by a deactivated silica gel column. Separative microdetermination of these chelates is accomplished within 12 min, and selective determination is also possible by choosing the detection wavelength of a UV detector.     

高效液相色谱法快速检测氨基葡萄糖含量

应用高效液相色谱法,建立了硫酸氨基葡萄糖氯化钾胶囊中氨基葡萄糖含量的快速测定方法。采用Hedera NH2色谱柱（250 mm ×4.6 mm,5 μm）,流动相为乙腈-磷酸缓冲液（ 65∶35）,流速为 1.0 mL/min,可变波长紫外检测器,检测波长为195 nm。 结果表明,在上述色谱条件下,氨基葡萄糖浓度在1.6~2.4 g/L范围内线性关系良好,检出限为7.81 mg/L,精密度（RSD,n=6）为0.53%;平均加标回收率为 100%,相对标准偏差为1.1%。该法准确、可靠,无需衍生反应,适用于硫酸氨基葡萄糖氯化钾胶囊中氨基葡萄糖的含量测定。     

A Low-Resolution Separation of C14 -Glyburide and Its Metabolites from Plasma Extracts Using a High-Performance Liquid Chromatograph Guard Column

Abstract

A low-resolution method for simultaneous, rapid determination of radiolabeled glyburide and its metabolites in human plasma is described. Plasma samples were extracted with ethyl acetate. Extracts were redissolved in 300 μl of mobile phase, and injected into a 3 cm guard column, which was incorporated as a loop in a six-port switching valve. C¹⁴-glyburide was collected as a single 4-min fraction at a flow rate of 4 ml per min.

Following collection of a 1-ml fraction, the column was backflushed with methanol to allow collection of the metabolites of glyburide. The mean value of recovered radioactivity was 95.5 ± 5.7%. The validity of the separation was verified in a high-resolution HPLC system and no cross contamination of the fractions was observed.     

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％。