左氧氟沙星-Al~(3+)-十二烷基硫酸钠体系胶束体系分光光度法测定左氧氟沙星

在B-R缓冲介质中,十二烷基硫酸钠(SDS)对左氧氟沙星(LVFX)-Al3+体系有显著的增敏作用,以此为基础建立了利用SDS增敏分光光度法测定LVFX的新方法。研究表明,体系吸光度与LVFX浓度在0.2~10μg/mL范围内呈良好的线性关系,相关系数r=0.9993,检出限为0.096μg/mL。将该方法用于盐酸左氧氟沙星片剂的测定,结果满意。     

左氧氟沙星-CdS-BSA体系荧光猝灭法测定左氧氟沙星

以六偏磷酸钠为稳定荆,巯基乙酸为修饰剂,水相合成了具有优异光学性质的CdS量子点.利用左氧氟沙星对CdS与牛血清白蛋白复合物的荧光有明显的猝灭作用,在536nm测定其荧光强度.结果表明,体系荧光猝灭程度与左氧氟沙星的浓度在0.2～20μg/mL范围内呈良好的线性关系,r=0.9994,检出限为0.0289μg/mL.方法已用于盐酸左氧氟沙星片剂和胶囊的测定,并与药典方法一致.     

库仑滴定法快速测定盐酸左氧氟沙星注射液中的左氧氟沙星含量

在1.0mol·L~(-1)氯化钾电解质溶液中,通过10.00mA的恒电流电解水产生OH-作为滴定剂,直接与盐酸左氧氟沙星发生酸碱中和反应,溶液pH 7.30为滴定终点,整个滴定过程可在5min左右自动完成,依据法拉第定律计算得到盐酸左氧氟沙星注射液中左氧氟沙星的含量。采用本方法测定盐酸左氧氟沙星对照品溶液,相对误差为0.16%;4种不同批次的盐酸左氧氟沙星注射液中左氧氟沙星的测定结果与标示值相符,测定值的相对标准偏差(n=6)小于0.40%,加标回收率在99.3%~100%之间。     

茜素红-镧-左氧氟沙星体系的共振瑞利散射及共振非线性散射光谱研究及应用

在pH6.0的HAc-NaAc缓冲液中,茜素红-镧与左氧氟沙星(LVFX)形成三元配合物,导致共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)均增强,光谱最大散射波长分别位于314 nm、570 nm和285 nm,对于RRS在0.02～1.2 mg/L、SOS在0.01～1.0 mg/L和FDS在0.01～1.0 mg/L范围内呈良好的线性关系,LVFX的检出限分别为4.00μg/L(RRS法)、9.16μg/L(SOS法)和4.42μg/L(FDS法),据此建立了灵敏的测定左氧氟沙星的共振线性和非线性光散射分析法。并以RRS法考察了茜素红-镧-左氧氟沙星体系的反应条件、影响因素等。方法可用于片剂、胶囊中左氧氟沙星的测定,同时以标准加入法对尿样和血样进行了分析。     

电位滴定法测定盐酸左氧氟沙星注射液中左氧氟沙星的含量

对测定盐酸左氧氟沙星注射液中有效成分左氧氟沙星含量的电位滴定法提出了改进,即在盐酸左氧氟沙星注射液样品中加入1.0~2.0倍于左氧氟沙星的物质的量的盐酸标准溶液,以0.050mol·L-1氢氧化钠标准溶液进行滴定,根据滴定曲线上第一个与第三个pH突跃点之间的体积差值计算左氧氟沙星的含量。按上述方法测定可消除样品中可能存在的游离盐酸或游离左氧氟沙星对测定带来的误差。4种不同批次注射液的测定结果与高效液相色谱法的测定结果相近,测定值的相对标准偏差(n=5)均小于0.30%。按标准加入法进行回收试验,回收率为97.6%~102%。     

电沉积铋膜电极差示脉冲溶出伏安法测定盐酸左氧氟沙星（英文）

盐酸左氧氟沙星分子中含有弱酸性有机胺结构,可与Zn(SCN)_4~(2-)形成离子缔合物沉淀.将沉淀分离溶解后,用差示脉冲溶出伏安法在原位形成铋膜电极上测定沉淀中锌(II)的含量,间接测定盐酸左氧氟沙星的含量,结果表明,采用铋膜电极伏安曲线峰形好、灵敏度高、峰电流值大,方法的线性回归方程为I=1.1401c-0.5309,相关系数R=0.9979,线性范围为5.0～60μg·m L~(-1),检出限为3.18×10~(-5)μg·m L~(-1),回收率为95%～101%,相对标准偏差RSD=2.87%。     

β-环糊精增敏亚甲基蓝荧光法测定左氧氟沙星

提出了一种增敏亚甲蓝荧光法测定左氧氟沙星新方法。左氧氟沙星(LVFX)与Br2发生加成反应,剩余的Br2能氧化亚甲蓝(MB)使其荧光降低,通过测定亚甲蓝的荧光强度间接测定左氧氟沙星(LVFX)的含量,加入适量β-环糊精(β-CD)使其荧光强度上升为原来的近2倍,大大提高其灵敏度。该体系最大激发波长为λex=660 nm,最大发射波长为λem=678 nm,线性范围为0.002～1.6 mg/L,检出限为0.0008 mg/L,相对标准偏差为0.13%。本方法可作为痕量左氧氟沙星的分析方法。     

自动石墨消解–电感耦合等离子体质谱法同时测定左氧氟沙星胶囊中7种金属元素

建立自动石墨消解-电感耦合等离子体质谱法(ICP-MS)同时测定左氧氟沙星胶囊中铅、铬、砷、镉、锡、铝、铁7种金属元素含量的方法。以HNO3-H2O2()体积比为1∶1为消解体系,采用自动石墨消解法消解左氧氟沙星胶囊样品,消解液除酸后,用5%硝酸溶液定容至50 mL,采用电感耦合等离子体质谱法对消解液进行测定,以内标法定量。铅、铬、砷、镉、锡、铝、铁的质量浓度在0.05~20.0μg/mL范围内与质谱响应值成良好的线性关系,相关系数均大于0.998,方法检出限为0.119~1.323μg/kg。样品加标回收率为91.2%~105.5%,测定结果的相对标准偏差为1.67%~3.46%(n=6)。该方法样品前处理简单,检出限低,测定结果准确,适用于左氧氟沙星胶囊等沙星类抗生素中多种金属元素残留的测定。     

高效液相色谱-串联质谱法测定膏霜类消毒产品中丙酸氯倍他索和盐酸左氧氟沙星

采用高效液相色谱-串联质谱法测定膏霜类消毒产品中丙酸氯倍他索和盐酸左氧氟沙星的含量。样品用乙腈提取20min,所得萃取液以Thermo Hypersil Gold色谱柱为分离柱,以不同体积比的0.1%(φ)甲酸溶液和乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子源多反应监测模式检测。2种化合物的质量浓度均在0.50~100μg·L~(-1)范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.06~0.009μg·kg~(-1)之间。在0.50,5.0,50.0μg·L~(-1)等3个浓度水平进行加标回收试验,回收率在90.0%~95.6%之间,测定值的相对标准偏差(n=5)在1.9%~4.0%之间。     

进食对左氧氟沙星在人体内代谢的影响

测定进食前后口服左氧氟沙星的尿药浓度，分析进食对左氧氟沙星在人体内代谢的影响。将受试者的尿液用0．01moL／L盐酸溶液稀释，用紫外分光光度法在326nm波长处测定左氧氟沙星的含量。左氧氟沙星的平均回收率为96．35％，线性范围为5．06～25．28μg／mL，测定结果的相对标准偏差为1．61％。健康受试者分别于进食前后口服左氧氟沙星，48h后尿药排泄量分别为给药量的87．43％和83．74％，经统计学分析无显著性差异，表明进食对左氧氟沙星在人体内的代谢没有显著影响。     

Determination of dopamine,epinephrine, and norepinephrine by open‐tubular capillary electrochromatography using graphene oxide molecularly imprinted polymers as the stationary phase

A novel capillary electrochromatography method was developed for the determination of dopamine (DA), epinephrine (EP), and norepinephrine (NE) by using a graphene oxide (GO) molecularly imprinted polymers (MIPs) coated capillary. In this article, GO was introduced as supporting matrix to synthesize MIPs in the presence of DA as template molecule. Then GO MIPs were used as the stationary phase in electrochromatography for the determination of DA, EP, and NE. The separation of these three analytes was achieved under the optimal conditions with a satisfactory correlation coefficients (R²) > 0.9957 in the range of 5.0–200.0 μg/mL for EP and NE, and 20.0–200.0 μg/mL for DA, respectively. The RSDs for the determination of three analytes were <6.19%, and the detection limits were 1.25 μg/mL for EP and NE, and 10.0 μg/mL for DA, respectively. Finally, this method was used for the determination of DA, EP, and NE in human serum and DA hydrochloride injection.     

高效液相色谱-荧光分析法同时测定人体尿液中黄蝶呤与异黄蝶呤

建立了高效液相色谱-荧光法同时测定癌症病人尿液中黄蝶呤及异黄蝶呤的新方法。选择荧光检测波长λex=345nm,λem=420nm。以磷酸盐缓冲溶液(pH=7.5)-甲醇(体积比为98∶2)为流动相,流速1.0mL/min,黄蝶呤与异黄蝶呤含量分别在0.0013～0.945μg/mL及0.00017～0.118μg/mL范围内与色谱峰面积呈良好的线性关系,线性相关系数分别为0.9999和0.9996,检出限分别为0.5ng/mL和0.05ng/mL,加标平均回收率在86.2%～107.5%之间。方法应用于癌症病人尿样分析,取得了较好的结果。     

A rapid and simple high-performance liquid chromatography method for the determination of human plasma levofloxacin concentration and its application to bioequivalence studies

A high-performance liquid chromatography method with fluorescence detection (HPLC-FLD) for the determination of levofloxacin in human plasma is described. Neutralized with phosphate buffer (pH 7.0), the sample (0.1 mL) was extracted with dichlormethane (1 mL). After voltex-mixing and centrifuged at 3000g for 6 min at 4 degrees C, the upper aqueous layer was aspirated using a micro vacuum pump and the organic layer was directly transferred to a clean test tube without pipetting. The organic solvent was evaporated and the residues were reconstituted with the mobile phase. Levofloxacin and terazosin (internal standard, IS) were chromatographically separated on a C(18) column with a mobile phase containing phosphate buffer (pH 3.0, 10 mm), acetonitrile and triethylamine (76:24:0.076, v/v/v) at a flow rate of 1 mL/min. The analytes were detected using fluorescence detection at an excitation and emission wavelength of 295 and 440 nm, respectively. The linear range of the calibration curves was 0.0521-5.213 microg/mL for levofloxacin with a lower limit of quantitation (0.0521 microg/mL). The retention times of levofloxacin and terazosin were 2.5 and 3.1 min, respectively. Within- and between-run precision was less than 12 and 11%, respectively. Accuracy ranged from -6.3 to 4.5%. The recovery ranged from 86 to 89% at the concentrations of 0.0521, 0.5213 and 5.213 microg/mL. The present HPLC-FLD method is sensitive, efficient and reliable. The method described herein has been successfully used for the pharmacokinetic and bioequivalence studies of a levofloxacin formulation product after oral administration to healthy Chinese volunteers.     

Determination of Herbicide Difenzoquat Methyl Sulfate in Citruses and Baby Juices by Kinetic‐Spectrophotometric Method and HPLC Method

The purpose of this paper is to present a new kinetic‐spectrophotometric method which involve inexpensive equipment and which can be applied by all analyst who have to determine difenzoquate methyl sulfate (DFQ) residues in citruses and baby juices. The method is based on the inhibited effect of DFQ on the oxidation of sulfanile acid (SA) by hydrogen peroxide in phosphate buffer in presence Cu(II) ion. The reaction was monitored spectrophotometrically by measuring the increase in absorbance of the reaction product at 370 nm. The proposed inhibited method permits determination of DFQ over the range 0.36 to 1.80 μg/mL and 1.80 to 7.20 μg/mL, with quantification limit of 0.184 μg/mL. The relative standard deviations are 0.73‐2.90% for the concentration interval of DFQ 1.80‐0.36 μg/mL. The method was successfully applied to determination of DFQ residues in citruses and baby juices. The HPLC method is used to verify the results. The results obtained for the same samples by the two methods are quite comparable.     

Kinetic Spectrophotometric Determination of Ranitidine

Two spectrophotometric methods were developed for the determination of ranitidine. The first method was a kinetic spectrophotometric method based on the catalytic effect of ranitidine on the reaction between sodium azide and iodine in an aqueous solution. The calibration graph was linear from 4–24 μg/mL. The drug was determined by measuring the decrease in the absorbance of iodine at 348 nm using a fixed time method. The decrease in the absorbance after 1 minute from the initiation of the reaction was related to the concentration of drug. The detection limit of the procedure was 0.76 μg/mL. The proposed procedure was successfully utilized in the determination of the drug in pharmaceutical preparations with mean recovery in the range of 99.83 ? 101.16%. The second method is a colorimetric method, which depends on the measurement of absorbances of tris (o‐phenanthroline) iron(II) [method 2A] and tris (bipyridyl) iron(II) [method 2B] complexes at 512 nm. The complexes obeyed Beer's law over the concentration range of 2–16 μg/mL and 4–40 μg/mL for methods 2A and 2B, respectively. The developed method has been successfully applied for the determination of ranitidine in bulk drugs and pharmaceutical formulations. The common excipients and additives did not interfere in its determination.     

Simultaneous determination of chlordiazepoxide and selected antidepressants using CZE

A simple CE method was developed and validated for the simultaneous determination of chlordiazepoxide (CHL), amitriptyline, and nortriptyline (mixture I) or the determination of CHL and imipramine (mixture II) using the same BGE. Sertraline and amitriptyline were used as internal standards for the first and second mixtures, respectively. The method allows amitriptyline to be completely separated from its impurity and main metabolite nortriptyline, which can be quantified from 0.2 μg/mL. The separation was achieved using 20 mM potassium phosphate buffer pH 5 containing 12 mM β‐cyclodextrin and 1 mM carboxymethyl‐β‐cyclodextrin. UV detection was performed at 200 nm and a voltage of 15 kV was applied on an uncoated fused‐silica capillary at 25°C. These experimental conditions allowed separation of the compounds to be obtained in 7 min. Calibration graphs proved the linearity up to 40 μg/mL for CHL, up to 100 μg/mL for amitriptyline and imipramine, and up to 5 μg/mL for nortriptyline. The accuracy and precision of the method have been determined by analyzing synthetic mixtures and pharmaceutical formulations. The analytical results were quite good in all cases indicating that the method was linear, sensitive, precise, accurate, and selective for both mixtures.     

HgCl2-头孢噻肟螯合阴离子与碱性三苯甲烷类染料相互作用的共振瑞利散射光谱及其分析应用

在pH为5.3～6.8的Britton-Robinson(BR) 缓冲溶液中, 头孢噻肟钠(CFTM)与HgCl2形成摩尔比为1∶1的螯合阴离子, 它能进一步与结晶紫、甲基紫、乙基紫、亮绿、碘绿、甲基绿和孔雀石绿等碱性三苯甲烷类染料反应形成三元离子缔合物, 导致共振瑞利散射(RRS)的显著增强. 最大RRS峰分别位于367, 367, 340, 367, 340, 340和340 nm附近, 在一定的CFFM质量浓度范围内散射强度与头孢噻肟钠的浓度均呈良好的线性关系. 用结晶紫、甲基紫、乙基紫、亮绿、碘绿、甲基绿和孔雀石绿体系测定头孢噻肟钠的线性范围和检出限(3σ) 分别为0.0090～3.5 μg/mL和2.7 ng/mL, 0.0092～3.5 μg/mL和2.8 ng/mL, 0.013～3.5 μg/mL和4.0 ng/mL, 0.010～3.5 μg/mL和3.1 ng/mL, 0.011～3.5 μg/mL和3.4 ng/mL, 0.012～4.0 μg/mL和3.5 ng/mL以及0.016～3.5 μg/mL和4.7 ng/mL, 其中以结晶紫体系灵敏度最高. 研究了适宜的反应条件和影响因素, 对离子缔合物的组成和离子缔合反应机理进行了探讨, 考察了共存物质的影响, 表明方法有良好的选择性, 据此发展了用HgCl2和碱性三苯甲烷类染料的灵敏、简便、快速测定痕量头孢噻肟钠的新方法.     

H-point standard addition method for simultaneous determination of phenylephrine hydrochloride,chlorpheniramine maleate,and paracetamol as a ternary mixture in pharmaceutical formulations

The simultaneous analysis of a ternary mixture containing paracetamol (PAR), phenylephrine hydrochloride (PHE), and chlorpheniramine maleate (CPM) was conducted without prior separation and using an advanced spectrophotometric method. The H-point standard addition and absorbance correction methods were selected to determine the compounds, which are highly overlapped spectra in pharmaceutical formulations. The method is based on the use of three different wavelengths of 296, 272, and 227 nm for the ternary mixture. The concentration of PAR was calculated directly at 296 nm because no interferences existed. Absorbance correction method was used to remove the role of PAR at 272 and 227 nm. The concentrations of the PHE and CPM compounds in the mixture were determined by using the H-point standard addition method. The results showed that simultaneous determination of PAR, PHE, and CPM could be conducted within the range of 1–33 μg/mL, 1–23 μg/mL, and 1–36 μg/mL, respectively. The relative standard deviations for the simultaneous determination of PHE, CPM, and PAR were 0.617, 2.76, and 1.71, respectively. The proposed method was implemented successfully for the simultaneous determination of PAR, PHE, and CPM in pharmaceutical formulations.     

超高效液相色谱法测定虾青素

建立超高效液相色谱法快速检测虾青素的方法。采用UPLC BEH C_8色谱柱(50 mm×2.1 mm,1.7μm),考察了流动相、流量及柱温对虾青素样品分离的影响,确定了最佳色谱条件:等度洗脱,流动相为甲醇–水(体积比为75∶25),流量为0.5 mL/min,柱温为40℃,检测波长为475 nm。虾青素的质量浓度在0.2~10.0μg/mL范围内与其色谱峰面积呈良好的线性关系,线性相关系数r=0.998 8,检出限(S/N=3)为0.1μg/mL,定量限(S/N=10)为0.2μg/mL。测定结果的相对标准偏差为0.41%(n=6),加标回收率为105.8%~110.3%。该方法快速、简单、可靠、灵敏、重复性好,可用于虾青素有关样品的快速检测。