高效液相色谱法测定硝苯地平片含量及其含量均匀度

采用高效液相色谱法测定了硝苯地平片含量及其含量均匀度。色谱柱为C18柱,流动相为V（甲醇）：V（三乙胺缓冲液,pH5．20）=68:32,紫外检测器,检测波长为237um。在此色谱条件下可得到较宽的线性范围和较高的回收率,其分解产物亦可得到良好的分离。     

反相液相色谱法测定α-甲氧基萘的含量

用反相液相色谱法分析了α-甲氧基萘的含量和其中的有害杂质。色谱条件：色谱柱Nucleosil－C18;流动相V（甲醇）：V（水）=90：10;紫外检测器,面积归一化法定量。方法的变异系数为0．29％。     

高效液相色谱法同时测定快安抗感冒液中5种组分的含量

采用高效液相色谱法（HPLC）同时测定快安抗感冒液中对乙酰氨基酚、咖啡因、盐酸甲基麻黄碱、马来酸氯苯那敏和愈创木酚甘油醚的含量。色谱柱为NOVA－PAKC_18柱,流动相为V（已腈）：V（0．03mol／L磷酸氢二铵）：V（0．004mol／L庚烷磺酸钠）：V（三乙胺）=12：44：43．5：0．5,并用磷酸调节pH值至3．0;检测波长220nm,柱温35℃。在此色谱条件下,各组分均获得良好分离。平均回收率为98．0％～100．3％,相对标准偏差小于1．8％。     

高效液相色谱法同时测定快安抗感冒液中5种组分的含量

 采用高效液相色谱法（HPLC）同时测定快安抗感冒液中对乙酰氨基酚、咖啡因、盐酸甲基麻黄碱、马来酸氯苯那敏和愈创木酚甘油醚的含量。色谱柱为NOVA－PAKC_18柱,流动相为V（已腈）：V（0．03mol／L磷酸氢二铵）：V（0．004mol／L庚烷磺酸钠）：V（三乙胺）=12：44：43．5：0．5,并用磷酸调节pH值至3．0;检测波长220nm,柱温35℃。在此色谱条件下,各组分均获得良好分离。平均回收率为98．0％～100．3％,相对标准偏差小于1．8％。     

高效液相色谱法测定香连丸及组方药材中5种活性组分的含量

建立了香连丸及组方药材中药根碱、巴马汀、小檗碱、木香烃内酯和去氢木香内酯的含量测定方法．采用反相高效液相色谱,Hypersil ODS（5μm,4．6mm×250mm）色谱柱,流动相为乙腈：水（70：30,V：V）,流速1．0mL／min,柱温30℃,检测波长为210n／n测定木香烃内酯和去氢木香内酯的含量;采用高效液相胶束色谱,Kromasil ODS（5la,m,4．6mm×150mm）色谱柱,流动相为0．2mol／LNaH2P04水溶液：7．00mmol／L十二烷基硫酸钠：乙腈（35：35：30,V：V：V）,流速1．0mL／min,柱温30℃,检测波长为350nm测定药根碱、巴马汀、小檗碱的含量．结果显示5种活性成分在适当的线性范围内均具有良好的线性关系（r大于0．9993）,平均回收率在87．67％～102．37％之间,RSD小于3．13％;结果表明方法简便、灵敏、准确,重现性好．     

超高效液相色谱-串联质谱法测定注射用头孢曲松钠中2-巯基苯并噻唑的含量

建立了一种超高效液相色谱-串联质谱法（UPLC-MS/MS）测定注射用头孢曲松钠中2-巯基苯并噻唑（MBT）基因毒性杂质含量。样品经甲醇提取,50%(V/V)乙腈稀释后,采用ACQUITY UPLC HSS T3色谱柱（2.1 mm×100 mm, 1.8μm）分离,乙腈-0.05%(V/V)乙酸（80∶20, V/V）为流动相,电喷雾离子源（ESI）,多反应监测（MRM）负离子模式扫描,外标法定量。MBT在0.11～10.92 ng/mL范围内线性关系良好（r2=0.9989）,检出限为0.03 ng/mL,定量限为0.08 ng/mL,平均回收率为96.8%,相对标准偏差（RSD）不大于3.5%。采用该方法检测抽检的14个厂家63批次样品中MBT杂质含量,59批次样品中有MBT检出。该方法适用于注射用头孢曲松钠中MBT的定性和定量分析。     

高效液相色谱法测定萨拉沙星

采用高效液相色谱法测定了萨拉沙星。色谱柱为μ－BondapakTMC18柱（3．9mm×300mm）,流动相为V（乙腈）：V（甲醇）：V（2mmol／L磷酸,用三乙胺调pH3．5）＝30：5：65,用二极管阵列检测器检测,检测波长278nm,得到了满意的分离效果。     

高效液相色谱法测定阿弗菌素含量

采用反相高效液相色谱法测定了阿弗菌素片中阿弗菌素的含量。色谱柱为ＴＳＫ－ＧＥＬＣ１８,流动相为甲醇∶水（７５∶２５）,检测波长２４５ｎｍ,可得到满意的分离效果。     

高效液相色谱法测定银杏外种皮中银杏酸的含量

建立了反相高效液相色谱法测定银杏外种皮中银杏酸含量的方法，色谱柱为Inertsil ODS-2，流动相为甲醇-3%Hac溶液（92:8，V/V），流速1.0mL/min；柱温40℃；紫外检测波长310nm；线性范围：0.572-10.30цg（相关系数R=0.9999）；检测限5.2ng(3a)。银杏外种皮提取物经一步硅胶柱层析预处理。实验测得银杏外种皮中银杏酸含量为5.46%；平均回收率为97.5%，RSD为1.9%(n=6)。该方法简便、准确、线性范围宽。     

高效液相法测定益母草中益母草碱含量研究

建立一种高效液相色谱(HPLC)检测鲜益母草及其制剂中益母草碱含量的方法。色谱柱为依利特Hypersil柱,流动相为0.00125 mol/L KH2PO4-CH3CN(87∶13,V/V),流速1 mL/min,柱温35℃,检测波长为276 nm。益母草碱的标准曲线回归方程是y=227 394x 1 292 605,r=0.9999(n=5)。该方法测定益母草及其制剂中益母草碱的含量,具有简便、准确及可靠的优点。     

高效液相色谱法测定盐酸芬氟拉明及其在片剂中含量

应用高效液相色谱法测定了盐酸芬氟拉明及其片剂的含量,使用２５ｃｍ×０．４６ｃｍｉ．ｄ．分析柱,填充ＨｙｐｅｒｓｉｌＢＤＳＣ１８（５μｍ）,检测波长２６４ｎｍ,流动相为Ｖ（乙腈）∶Ｖ（０．４ｍｏｌ／Ｌ乙酸铵）∶Ｖ（三乙胺）＝３０∶７０∶２。选用咖啡因作内标物,用内标法进行定量测定,在０．１～０．５ｇ／Ｌ范围内呈良好的线性关系,相关系数为０．９９９９。片剂的平均回收率为９９．９８％。方法简单、快速、灵敏度高、重现性好。     

高效液相色谱法测定磷酸苯丙哌林片的含量

 采用反相高效液相色谱法 ,以醋酸可的松为内标 ,测定磷酸苯丙哌林片的含量。色谱柱为ODS柱 ,以甲醇 水 冰醋酸 三乙胺溶液 (体积比为 6 0∶35∶5∶0 1)为流动相 ,检测波长为 2 70nm ,磷酸苯丙哌林在 9 96mg/L～ 49 8mg/L范围内有很好的线性关系 (r=0 9998) ,平均回收率为 99 91% (n =5 ) ,RSD =0 43%。     

Determination of nifedipine in dog plasma by high‐performance liquid chromatography with tandem mass spectrometric detection

Nifedipine is a dihydropyridine calcium channel blocker used widely in the management of hypertension and other cardiovascular disorders. In this work, a simple, rapid and sensitive liquid chromatography/tandem mass spectrometry method was developed and validated to determine nifedipine in dog plasma using nimodipine as the internal standard. Chromatographic separation was carried out on a C₈ column. The mobile phase consisted of a mixture of acetonitrile, water and formic acid (60:40:0.2, v/v/v) at a flow rate of 0.5 mL/min. Detection was performed on a triple quadrupole tandem mass spectrometer in selected reaction monitoring mode via an atmospheric pressure chemical ionization source. The method has a lower limit of quantification of 0.20 ng/mL with consumption of plasma as low as 0.05 mL. The linear calibration curves were obtained in the concentration range of 0.20–50.0 ng/mL (r = 0.9948). The recoveries of the liquid extraction method were 74.5–84.1%. Intra‐day and inter‐day precisions were 4.1–8.8 and 6.7–7.4%, respectively. The quantification was not interfered with by other plasma components and the method was applied to determine nifedipine in plasma after a single oral administration of two controlled‐release nifedipine tablets to beagle dogs. Copyright © 2013 John Wiley & Sons, Ltd.     

高效液相色谱-四极杆飞行时间质谱法快速鉴定硝苯地平原料药中杂质

利用高效液相色谱-四极杆飞行时间质谱法(HPLC-QTOF MS)对硝苯地平原料药的4种杂质进行了在线的质谱分析。色谱柱为Kromasil C18(250 mm×4.6 mm, 5 μm),流动相为甲醇-水(60:40, v/v),检测波长为235 nm。通过紫外检测器和四极杆飞行时间质谱仪在线检测,分离并检测了硝苯地平及其杂质,获得了它们的紫外光谱和质谱数据;通过比较加合质子的硝苯地平和杂质的准分子离子的碎裂特征,直接推断出了3个杂质可能的结构,其中1个为未知杂质;采用与对照品保留时间和质谱数据的比对,确定了另外1个杂质的结构。实验表明,HPLC-QTOF MS可以快速鉴定硝苯地平中杂质的化学成分。     

Cathodic adsorptive stripping square-wave voltammetric determination of nifedipine drug in bulk,pharmaceutical formulation and human serum

Nifedipine is a calcium-channel antagonist drug used in the management of angina pectoris and hypertension through inhibition of calcium influx. A fully validated sensitive cathodic adsorptive stripping square-wave voltammetry procedure was optimized for the determination of the drug at trace levels. The procedure was based on the reduction of the nitrophenyl group after the interfacial accumulation of the drug onto a hanging mercury drop electrode in Britton-Robinson buffer of pH 11.0. The optimal conditions of the procedure were found to be: accumulation potential=-0.9 V vs. Ag/AgCl/KCl(s)), accumulation time=30 s, scan increment=10 mV, pulse amplitude=50 mV and frequency=120 Hz. Under these conditions, a well-defined peak was obtained; its peak current showed a linear dependence on drug concentration in the range of 2x10(-9)-2x10(-7) mol L(-1) bulk nifedipine. The mean recoveries based on eight replicate measurements for 1x10(-8) and 5x10(-8) mol L(-1) bulk nifedipine solutions were 98.46+/-0.86% and 98.23+/-0.92%, respectively. A detection limit of 3.42x10(-10) mol L(-1) bulk nifedipine was achieved. The procedure was successfully applied for assay of the drug in tablets and spiked human serum with mean recoveries of 101.95+/-1.42% and 98.70+/-0.63%, respectively. The limit of detection of the drug in spiked human serum was found to be 3.90x10(-10) mol L(-1).     

Analysis of Thyroidal Amino Acids in Pharmaceutical Preparations. I - Reverse Phase High Pressure Liquid Chromatography Analysis of Sodium Liothyronine from Tablets

Abstract

A simple, sensitive and specific assay method was developed for the assay of sodium liothyronine (T₃Na) from tablets. Sodium liothyrorn'ne was extracted from powdered tablets with a solvent system consisting of butanol and dilute hydrochloric acid. The solvent was removed under vacuum and the residue was dissolved in ammonical methanol. An aliquot of this solution was injected on a μBondapak C₁₈ column and the elution was carried out with a mobile phase consisting of methanol:water:phosphoric acid (55:45: 0.1). The effluent was monitored by U. V. detection at 254 nm. A linear calibration curve was obtained in the range of 10 to 250 ng on column with a precision of ±4% (C. V.). The internal standard consisted of 3, 3′, 5-triiodothyronine (T3′ or RT₃). The usefulness of an alternate compound, 3, 5-diiodo-3′, 5′-dibromothyronine, which is not endogenous, was also demonstrated as an internal standard.     

Development and validation of a stability-indicating LC method for the assay of lodenafil carbonate in tablets

A stability-indicating liquid chromatographic method has been developed for the quantitative determination of lodenafil carbonate in tablets. The method employs a Synergi Fusion C18 column (250 × 4.6 mm, i.d., 4 μm particle size), with mobile phase consisting of a mixture of methanol-acetic acid 0.1% pH 4.0 (65:35, v/v) and UV detection at 290 nm, using a photodiode array detector. A linear response (r = 0.9999) was observed in the range of 10-80 μg/mL. The method showed good recoveries (average 100.3%) and also intra and inter-day precision (RSD < 2.0%). Validation parameters as specificity and robustness were also determined. Specificity analysis showed that no impurities or degradation products were co-eluting with the lodenafil carbonate peak. The method was found to be stability-indicating and due to its simplicity and accuracy can be applied for routine quality control analysis of lodenafil carbonate in tablets.     

Determination of vitamin B12 in multivitamin tablets and fermentation medium by high-performance liquid chromatography with fluorescence detection

A novel method for the determination of vitamin B12 by high-performance liquid chromatography with fluorescence detection is reported. The method was simple and highly sensitive with good precision. Vitamin B12 was analyzed by HPLC on a muBondapak C18 column (300x3.9 mm, 10 microm) with methanol-water (30:70) as mobile phase and fluorescence detection at 305 nm (with excitation at 275 nm). The calibration graph was linear from 1.000 to 100.0 ng ml(-1) for vitamin B12 with a correlation coefficient of 0.998 (n=6). The detection limit was 0.1 ng ml(-1). The method was successfully applied to the determination of vitamin B12 in vitamin B12 tablets, multivitamin tablets and fermentation medium. The recovery was from 94 to 102% and the relative standard deviation was in the range of 1.8 to 4.1%.