高效液相色谱法测定水产品中的恶喹酸

建立了高效液相色谱法测定水产品中恶喹酸残留量的方法。样品用二氯甲烷提取后，除去溶剂，用稀盐酸和正己烷处理，去除残渣中的脂肪，再用二氯甲烷萃取，浓缩至干后用甲醇定容。以0.002mol/L磷酸溶液－乙腈－四氢呋喃（体积比为65：20：15）为流动相，在ODS反相色谱柱上分离后，用荧光检测器测定，外标法定量。方法的线性范围为5－5000ng/mL，线性回归方程为A＝9.426c-2.123，相关系数r=0.9988，检出限为1μg/kg，回收率为93.0%-96.0%，相对标准偏差为3.7%-6.2%。     

柱前衍生高效液相色谱法测定猪肉中5种青霉素残留量

样品采用乙腈直接提取,离心分离及用液-液分配和固相萃取（C18柱）净化方式,经衍生后,用液相色谱紫外检测器测定猪肉中5种青霉素残留量。使用的分离柱是Nova Pak C18柱,流动相为乙腈和磷酸盐混合液。方法检出限0.02mg/kg,回收率为70.9%-96.5%,相对标准偏差为3.10%-6.71%。     

气相色谱法测定柴胡注射液中环己醇

建立了气相色谱法测定柴胡注射液中环己醇的定量分析方法，以正己烷为萃取剂，水蒸汽蒸馏浓缩富集提取液，用PEG－20M柱，氢火焰检测器（FID）检测。结果表明，柴胡注射液中环己醇质量浓度在10.0μg/mL-120.0μg/mL范围内呈良好的线性关系（r=0.998），回收率为92 .3%-95.1%，RSD为1.1%－1.2%。     

反相离子对高效液相色谱法测定硫酸软骨素

以四甲基氯化铵作为离子对试剂，采用乙腈-2.28mmol/L四甲基氯化铵水溶液（5:95)作为流动相，选用C18色谱柱分离硫酸软骨素和杂质，建立了测定硫酸软骨素含量的反相离子对高效液相色谱方法。该方法的线性范围为0.4-8.0μg，回收率为98.8%-100.3%，相对标准偏差为0.17%-0.53%。该方法的精密度和准确度较高。     

液相色谱法测定鳗鱼中的孔雀石绿

用高效液相色谱法测定鳗鱼组织中孔雀石绿的残留量。鱼体中残留的孔雀石绿在酸性介质下，经高速均质后，用乙腈均质提取，合并提取液，用二氯甲烷再次萃取，有机相过无水硫酸钠和氧化铝复合小柱后浓缩至干，用盐酸羟胺和流动相定容。以乙酸盐缓冲溶液和乙腈为流动相，在KR60－5氰柱上分离后，用可见光检测器在618nm处测定吸光强度，外标法定量。其检出限为1μg/kg，回收率为93.5%-99.6%，相对标准偏差RSD为6.54%-11.0%。     

火焰原子吸收分光光度法测定饲料中的钙含量

采用硝酸锶作干扰制剂，不经分离，直接用火焰原子吸收分光光度法测定饲料中的钙含量。该方法的线性范围为0-7.0μg/ml。线性回归方程为A=37.5169C 1.1143，相关系数r=0.9998，相对标准偏差为0.59%-1.53%，回收率为98%-100.5%。该方法简便、快速。     

离子色谱法测定面粉及面粉制品中溴酸盐

提出了离子色谱法测定面粉及面粉制品中溴酸盐的测定方法.样品经水提取,固相萃取,银柱净化处理后进行色谱分析.采用色谱柱为IonPac AS19型阴离子分离柱(2 mm×250 mm);ASRS-ULTRAⅡ2 mm阴离子抑制器,检测器为ED50抑制型电导检测器.方法的线性范围在200μg·L-1内.检出限为0.01 mg·kg-1,加标回收率为92.9%～99.5%,相对标准偏差为(n=6)小于5%.     

反相高效液相色谱法测定鼠胆汁中游离与结合型胆汁酸

建立了一种柱前衍生反相高效液相色谱荧光检测大鼠胆汁中游离与结合型胆汁酸的方法.以4-溴甲基-7-甲氧基香豆素为衍生剂,月桂酸为內标,Waters Nova C18色谱柱分离,采用甲醇/乙腈和水梯度洗脱,荧光激发波长(λex)330 nm,发射波长(λem)400 nm,內标标准曲线法定量.各胆汁酸在5-2 400μmol/L范围内线性良好,r为0.998 9-0.999 7.最低检出限为1.2-2.5μmol/L.精密度日内在1.05%-3.67%之间,日间在3.16%-6.83%之间.平均回收率为87.8%-106.7%.该方法灵敏、重复性好,分析时间短,线性范围宽,适合于科研工作中对鼠胆汁中各胆汁酸进行定量检测.     

火焰原子吸收分光光度法测定复合肥料中的钾含量

以K404.4nm作为分析线，研究了火焰原子吸收分光光度法测定复合肥料中钾含量的方法。该方法的线性范围为0－208mg/L，线性回归方程为A＝0.0026c-0.0100，相关系数r=0.9992，RSD为2.4%-5.0%，回收率为95.6%-101.3%。该方法的测定结果与四苯硼酸钾重量法基本一致，且方法简便、快速。     

气相色谱法同时测定甲醇中共存杂质和微量芳烃

提出了甲醇中共存杂质(丙酮、乙酸甲酯、乙醇)和微量芳烃(乙苯、对二甲苯、间二甲苯和邻二甲苯)含量的气相色谱测定方法。用INNOWAX色谱柱,采取程序控制柱温升温,用氢火焰离子检测器,各种化合物完全分离。丙酮、乙酸甲酯和乙醇的线性范围为4.0～20mg.L-1,各芳烃化合物的线性范围为0.4～2.0mg.L-1。方法用于甲醇样品的分析,加标回收率在88%～114%之间,相对标准偏差(n=7)为2.56%～4.68%。     

离子色谱法测定浴盐中的阴、阳离子

用离子色谱法测定浴盐中的Na^ 、K^ 、Mg^2 、Ca^2 、Cl^-、Br^-、SO4^2-时，分离阳离子的色谱柱为ICS-C25阳离子交换柱，淋洗液为2.0mmol/L均苯四甲酸溶液，流速为0.6mL/min；分离阴离子时的色谱柱为shim-pack IC-Al阴离子交换柱，淋洗液为2.5mmol/L邻苯二甲酸溶液－2.4mmol/L三羟基氨基甲烷溶液（体积比为1：1），流速为1.0mL/min。所测离子Na^ 、K^ 、Mg^2 、Ca^2 、Cl^-、Br^-、SO4^2-在较宽浓度范围内有良好的线性关系，回收率为94.7%-102.4%，检出限为0.001-0.02mg/L，相对标准偏差为1.03%-1.63%。     

Extraction-spectrophotometric determination of boron with 4,6-Di-tert-butyl-3-methoxycatechol and ethyl violet

4,6-Di-tert-butyl-3-methoxycatechol (DBMC) has been developed as a new reagent for boron, the complex anion formed being extracted as an ion-associate with Ethyl Violet into toluene, and the absorbance measured at 610 nm. The calibration graph is linear up to 0.43 mug of boron, the molar absorptivity is 1.02 x 10(5) 1.mole(-1).cm(-1) and the relative standard deviation 1.2%. The method has been applied to the determination of boron in sea-water and river water with satisfactory results.     

Determination of serum selenium by hydride generation flame atomic absorption spectrometry

Serum is rapidly digested with a mixture of nitric and perchloric acids at a temperature of 180 +/- 10 degrees C, and hydrochloric acid is used to reduce selenium(VI) to selenium(IV). Selenium is determined by hydride generation flame atomic absorption spectrometry. The results show that this method has the advantages of being sensitive, accurate, rapid and simple. After the serum is digested and diluted, 4.0 ml is taken for the determination. The characteristic concentration, detection limit, variation coefficient, recovery rate and linear range are 2.93 mug 1(-1), 1.55 mug l(-1), 1.6-5.0%, 97.3-99.2% and 0.0-320.0 mug l(-1) respectively. Serum at 4 degrees C and in frozen state can be preserved for at least 7 and 14 days, respectively.     

New liquid-membrane electrodes for direct determination of atropine in pharmaceutical preparations

Solutions of atropinium 5-nitrobarbiturate in n-octanol and atropinium picrolonate in p-nitrotoluene are used as novel liquid ion-exchangers in electrodes that respond to the atropine cation. The performance characteristics of the two electrodes are almost identical: the response is linear for 10(-5)-10(-2)M atropine with a slope of 56.5 +/- 1 mV/concentration decade. The static response times are 30-90 sec and the potential readings are stable over the pH range 3-8. There is negligible interference from a number of inorganic and organic cations, and some common excipients. In the direct determination of 1-200 mug/ml of atropine, the average recovery with both electrodes is 98% (mean standard deviation 1.7%). Atropine has been determined in some pharmaceutical preparations with an average recovery of 98% (standard deviation 1.9%), the results being in agreement with those obtained by standard methods.     

Fast determination of calcium, magnesium and zinc in honey using continuous flow flame atomic absorption spectrometry

A procedure is described for the rapid determination of calcium, magnesium and zinc in honey with no previous mineralization stage. The samples are dissolved in a solution containing dilute hydrochloric acid and a lanthanum salt, and then directly introduced into the flame atomic absorption spectrometer by means of a simple continuous-flow manifold. The computer-controlled system performs an automatic on-line dilution of the solutions, in this way decreasing matrix effects due to the organic matter content and allowing analytical signals within the linear response range to be obtained. Calibration is carried out against aqueous standards. Reproducibilities for calcium and magnesium measurements in the honey samples are close to +/-3%. The detection limit for zinc is 0.2 mug g(-1), the reproducibility obtained for a honey sample containing 1.7 mug g(-1) zinc being +/-5.2%. The results agree with those obtained by means of a lengthy mineralization-based procedure, the main advantages of the non-conventional methodology reported being automation, saving of time and a decrease in the contamination risk.     

Development and validation of a liquid chromatography/tandem mass spectrometry method for the determination of the novel anticancer agent 17-DMAG in human plasma

An accurate, sensitive, robust and selective liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin hydrochloride (17-DMAG) in human plasma has been developed and validated. Plasma samples were prepared by liquid/liquid extraction with ethyl acetate. The chromatographic separation was achieved within 9 min on a Synergy Polar column with a linear gradient and a mobile phase consisting of methanol and 0.1% formic acid in water. Detection of 17-DMAG and the internal standard (IS), olomoucine, was achieved by MS/MS with electrospray ionisation in positive ion mode. The calibration curve, ranging from 1.89 to 1890 nM, was linear r > 0.994 using a 1/y2 weighted linear regression. The assay showed no significant interferences from endogenous compounds. The lower limit of quantitation (LLOQ) was 1.89 nM, using 250 microL of plasma, with inter-assay precision (%RSD) and accuracy (%RE) values of 11.6% and -5.8%, respectively. Intra-assay precision ranged from 7.8-13.6%. The method described here is being used to evaluate the pharmacokinetic profiles of 17-DMAG given as a once weekly infusion in patients with advanced solid tumours.     

High-performance liquid-chromatographic determination of rifampicin in plasma and tissues

A HPLC-UV method has been developed for assaying rifampicin in plasma and liver. The assay involved a liquid-liquid extraction procedure with dichloromethane-pentane (1:1). An Ultrabase-C18 column and a simple mobile phase consisting of a water (pH 2.27)-acetonitrile (40:60, v/v) mixture were used. The flow-rate was 1 ml/min and the effluent was monitored at 333 nm. Results from the HPLC analyses showed that the assay method is linear in the ranges 0.1-1 and 1-50 microg/ml for plasma, and 0.6-40 microg/g for liver. Intra- and inter-day R.S.D. were below 15% for all the sample types. Recoveries averaged 83 and 95% for plasma and liver, respectively. The method is being successfully applied to determine rifampicin in plasma and liver samples taken during pharmacokinetic studies in rats.     

Assay of metyrapone, metyrapol and the isomeric mono-N-oxides of metyrapone in biological fluids by high-performance liquid chromatography

A sensitive high-performance liquid chromatographic (HPLC) method for the analysis of metyrapone [2-methyl-1,2-di-(3-pyridyl)-1-propanone], its reduced metabolite metyrapol and metyrapone mono-N-oxide metabolites in biological fluids is reported. These components were extracted into dichloromethane (2 x 5 ml) from alkalinised microsomal incubates, urine and blood (final pH about 12.5), or from cytosolic incubates at pH 7.4 (final aqueous volume 2-4 ml). Recoveries were in the range 70-100% under these conditions. The intact drug and metabolites were separated by reversed-phase HPLC with ultraviolet detection at 261 nm. All calibration curves were linear (correlation coefficient greater than 0.997). For the analysis of hepatic microsomal or cytosolic incubates, the coefficient of variation was less than 10% for samples over the range 2.5-250 nmol/ml N-oxides and 10-250 nmol/ml metyrapol. Measurement of metyrapone and metyrapol in rat blood (0.25-ml sample volume) was linear in the ranges 4.4-265 and 26-263 nmol/ml, respectively, the lower concentration being the limit of detection. The coefficient of variation was less than 20% for samples over the ranges tested for both these compounds. The N-oxide metabolites were not detectable in blood using this assay, their concentrations being below the limit of detection.     

High-performance capillary electrophoresis of proteins. Sodium dodecyl sulphate-polyacrylamide gel-filled capillary column for the determination of recombinant biotechnology-derived proteins.

Fused-silica capillary columns were filled with sodium dodecyl sulfate-polyacrylamide gel and the column effluent was monitored at 214 nm using a commercially available high-performance capillary electrophoresis (HPCE) instrument to separate and rapidly quantify recombinant biotechnology-derived proteins. An excellent linear relationship (r greater than 0.999) exists between the peak migration time and the molecular weights of reference proteins in the range 10,000-100,000 and 40,000-200,000 dalton by use of the capillary columns filled with acrylamide gel at a T composition of 5% and 3%, respectively. The relative standard deviation (R.S.D.) of the peak migration time is ca. 1%. Theoretical plates of 5 X 10(5)-1 X 10(6) per metre are routinely being obtained. Calibration graphs of peak area versus weight of recombinant biotechnology-derived proteins are linear (r greater than 0.999) and the proteins may be quantified with an R.S.D. of ca. 3-7%. As little as 50 nmol of a protein may be quantified and an impurity peak of molecular weight ca. 1500 less than that of the parent compound (ca. 60,000 dalton) may be differentiated by HPCE with a gel-filled capillary column.     

线性扫描阳极溶出伏安法测定酒中的铅

采用线性扫描阳极溶出伏安法测定酒中铅的含量，在0．1mol/L盐酸底液中，铅的加标回收率为97．4％～101．3％，测定结果的相对标准偏差为0．76％～3．32％，线性范围为0．02～1．10mg／L。