Determination of trovafloxacin in human body fluids by high-performance liquid chromatography.

For the quantitative determination of trovafloxacin (a new naphthyridinone antibacterial agent) in serum and urine a simple isocratic HPLC method with fluorimetric detection is described. Serum was deproteinised with a mixture of acetonitrile and perchloric acid. The protein-free extract was separated on a reversed-phase column (Nucleosil 100-5 C18) and quantified by means of fluorescence (excitation 275 nm, emission 405 nm). The mobile phase consisted of a mixture of 250 ml acetonitrile and 750 ml distilled water containing 10 mmol/l tetrabutylammonium phosphate. Urine was diluted with 0.25 mol/l phosphoric acid 1:20 (v/v) which was adjusted to pH 3.6 with sodium hydroxide solution. Diluted urine samples were separated on a cation-exchange column (Nucleosil 100-5 SA) and also detected by means of fluorescence. Trovafloxacin was sufficiently separated from endogenous compounds. Results of validation are given. The method was applied successfully to a study of healthy volunteers.     

Synthesis,Characterization and Application of Organic-inorganic Hybrid and Carbaryl-imprinted Capillary Monolithic Column

Organic-inorganic hybrid and carbaryl-imprinted capillary monolith was synthesized via methacrylic acid（MAA） as functional monomer, γ-methacryloxypropyltrimethoxysilane（γ-MAPS） as crosslinker and carbaryl as template molecule in an acetonitrile/dichloromethane mixture（1：4, volume ratio）. With the capillary column obtained from this monolith, three carbamates（carbaryl, fenobucarb and metolcarb） were separated effectively by electrochromatography with the kMIp/kNlP values of 7.57, 1.27 and 1.64, respectively. In 20 mmol/L phosphate buffer solution（pH=3.5） with 30%（volume fraction） of acetonitrile, carbaryl was separated directly from the three-carbamate mixture（carbaryl, fenobucarb and metolcarb） with an effective 15 cm-length imprinted column.     

液相色谱-质谱联用法测定牛奶中14种青霉素及相应青霉噻唑酸残留量

利用超高效液相色谱-串联质谱法(UPLC-MS/MS)同时测定牛奶中的7种青霉素类抗生素以及7种相应的青霉噻唑酸。样品经乙腈沉淀蛋白,上清液N2吹干后,用水溶解,加入正己烷萃取除去脂肪;提取液经ACQUITY UPLCBEH C18柱分离,乙腈-乙酸铵+甲酸水溶液洗脱。14种物质峰分离良好,定量限范围在5～20μg/kg。在10～50ng/mL质量浓度范围内线性良好,相关系数均大于等于0.999,牛奶中的加标回收率在90%～98%。     

Determination of Magnolol and Honokiol by Non-aqueous Capillary Electrophoresis

Introduction Capillaryelectrophoresis(CE),ahighefficiency separationtechnique,hasrapidlydevelopedsince1981[1].Notonlyhavedifferentmodesbeenrepor ted[1—3],butalsosomenon aqueouselectrophoresis media[4]havebeenapplied.Theimportantproperties ofnonaqueousmed…     

液相色谱-串联质谱法测定牛奶中5种多肤类抗生素

建立了牛奶中杆菌肽、粘杆菌素A、粘杆菌素B、维吉尼霉素和万占霉素5种多肽类抗生素的反相液相色谱-串联质谱(HPLC-MS/MS)检测方法.牛奶样品经甲醇-0.1%甲酸水提取后,用4%三氯乙酸乙睛除蛋白,液-液萃取后,采用0.1%甲酸(A)和0.1%甲酸乙腈(B)作为流动相进行梯度洗脱.质谱(ESI+)采用多离子检测模式...     

超高效液相色谱–串联质谱法测定生活饮用水中10种农药残留

采用超高效液相色谱–串联质谱法测定生活饮用水中10种农药残留。水样直接进样,选用Waters ACQUITY UPLC~BEH C_(18)柱分离,以乙腈–0.1%甲酸溶液为流动相进行梯度洗脱,质谱选用多反应监测模式分析,10种农药的质量浓度在0.5~50μg/L范围内与色谱峰面积呈线性相关,检出限(3S/N)在0.03~0.50μg/L之间,测定值的相对标准偏差在1.14%~9.91%之间,加标回收率在91.6%~107.1%之间。该法简便准确,适用于生活饮用水中农药残留的检测。     

Determination of acetylsalicylic acid and its major metabolite, salicylic acid, in human plasma using liquid chromatography-tandem mass spectrometry: application to pharmacokinetic study of Astrix in Korean healthy volunteers

The first liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for determination of acetylsalicylic acid (aspirin, ASA) and one of its major metabolites, salicylic acid (SA), in human plasma using simvastatin as an internal standard has been developed and validated. For ASA analysis, a plasma sample containing potassium fluoride was extracted using a mixture of ethyl acetate and diethyl ether in the presence of 0.5% formic acid. SA, a major metabolite of ASA, was extracted from plasma using protein precipitation with acetonitrile. The compounds were separated on a reversed-phase column with an isocratic mobile phase consisting of acetonitrile and water containing 0.1% formic acid (8:2, v/v). The ion transitions recorded in multiple reaction monitoring mode were m/z 179 --> 137, 137 --> 93 and 435 --> 319 for ASA, SA and IS, respectively. The coefficient of variation of the assay precision was less than 9.3%, and the accuracy exceeded 86.5%. The lower limits of quantification for ASA and SA were 5 and 50 ng/mL, respectively. The developed assay method was successfully applied for the evaluation of pharmacokinetics of ASA and SA after single oral administration of Astrix (entero-coated pellet, 100 mg of aspirin) to 10 Korean healthy male volunteers.     

The use of acetone as a substitute for acetonitrile in analysis of peptides by liquid chromatography/electrospray ionization mass spectrometry

The recent worldwide shortage of acetonitrile has prompted interest in alternative solvents for liquid chromatography/mass spectrometry (LC/MS). In this work, acetone was substituted for acetonitrile in the separation of a peptide mixture by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) and in the positive electrospray ionization mass spectrometry (ESI‐MS) of individual peptides. On both C12 and C18 stationary phases, the substitution of acetone for acetonitrile as the organic component of the mobile phase did not alter the gradient elution order of a five‐peptide retention standard, but did increase peak width, shorten retention times, and increase peak tailing. Positive ESI mass spectra were obtained for angiotensin I, bradykinin, [Leu⁵]‐enkephalin, and somatostatin 14 dissolved in both acetonitrile/water/formic acid (25%/75%/0.1%) and acetone/water/formic acid (25%/75%/0.1%). Under optimized ESI‐MS conditions, the mass spectral response of [Leu⁵]‐enkephalin was increased two‐fold when the solvent contained acetone. The substitution of acetone for acetonitrile resulted in only slight changes in the responses of the remaining peptides. A higher capillary voltage was required for optimum response when acetone was used. Compared with acetonitrile/water/formic acid (50/50/0.1%), more interfering species below m/z = 140 were found in the ESI‐MS spectra of acetone/water/formic acid (50/50/0.1%). Copyright © 2009 John Wiley & Sons, Ltd.     

Impurity-profiling UPLC methods for quantitative analysis of some antiemetics formulated with pyridoxine

Cyclizine hydrochloride (CYC) and meclozine hydrochloride (MEC) are antihistaminic drugs generally co-formulated with pyridoxine hydrochloride (PYR) to treat nausea and vomiting in pregnancy. Several analytical techniques have been applied for the determination of CYC or MEC with PYR, but determination of CYC impurity; benzhydrol (BEH) or MEC impurity; or 4-chlorobenzophenone (BEP) has not been paid attention to. Therefore, micellar UPLC method is introduced for analysis of ternary mixtures containing PYR together with both CYC and BEH (mixture I) or MEC and BEP (mixture II). Chromatographic separation was achieved using a Hypersil gold C₈ column (50 × 2.1 mm, 1.9 μm) using 0.01 M sodium dodecyl sulfate modified to pH 3.5 using phosphoric acid:acetonitrile (45:55 by volume) for mixture I and 0.1% sodium dodecyl sulfate, 0.1% sodium bicarbonate adjusted to pH 2.6 by phosphoric acid:acetonitrile (47:53 by volume) for mixture II as mobile phases. The separated peaks were detected at 230 and 245 nm for mixtures I and II, respectively. The adopted methods were validated in conformance with the International Conference on Harmonization (ICH) recommendations and were properly applied in commercial pharmaceutical formulation analysis. Comprehensive ecological comparison was achieved, confirming a higher ecological value of the presented methods compared to the earlier reported methods.     

Monitoring propofol serum levels by rapid and sensitive reversed-phase high-performance liquid chromatography during prolonged sedation in ICU patients.

A quick and sensitive reversed-phase high-performance liquid chromatography (HPLC) method has been developed in order to determine the concentration of Propofol (2,6 diisopropylphenol) in human serum. Propofol can be isolated from serum by adding 0.5 mL precipitating solution. This consists of an acetonitrile and perchloric acid (67:33, v/v) mixture, which also contains dibutylphthalate (2 mg/100 mL) as internal standard. The sample is then mixed for 1 min on a vortex-mixer. The endogenous serum substances precipitated by acetonitrile and perchloric acid are further separated by centrifugation. The supernatant is directly injected into the HPLC system. A 250- x 4.6-mm column, packed with 10-microns Spherisorb reversed-phase octadecylsilane particles (C18), is used for chromatographic separation. The mobile phase consists of an acetonitrile-water mixture (67:33 ratio) with 0.4 mL acetic acid (pH 4). Propofol is monitored by a UV-visible detector at 270 nm and 0.1-0.002 absorbance units full scale (AUFS). The detection limit of Propofol (in human serum) is 0.1 mg/L for a 20-microL injection volume. The time of the assay is less than 20 min, including sample preparation.     

毛细管电泳法测定非水溶性药物——复方降压片

在区带电泳中,应用在背景电解质中加入乙腈的方法对复方降压片的两种主要成分利血平、双氢氯噻嗪进行了分离和定量测定。５次重复测定的相对标准偏差小于３％,检出限分别为０．２６９ｍｇ／Ｌ和１．８４ｍｇ／Ｌ,并对ｐＨ值、磷酸盐浓度及乙腈用量进行了考察。     

A mixed matrix of 3-hydroxypicolinic acid and pyrazinecarboxylic acid for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of oligodeoxynucleotides

A mixed matrix of 3-hydroxypicolinic acid (3-HPA) and pyrazinecarboxylic acid (PCA) was used for analysis of a variety of synthetic oligodeoxynucleotides ranging in length from 8-108-mers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The experimental results showed that DNA segments with masses in the range from 5000 to 10,500 Da can be analyzed with high resolution (isotopic peaks resolved) when 3-HPA/PCA was prepared by mixing saturated 3-HPA solution and saturated PCA solution (in 50% of a 0.5 mol/L solution of diammonium hydrogen citrate plus 50% acetonitrile) at the volume ratio of 4:1. Each component of a mixture of d(A)1-10 gave a well-resolved peak. Moreover, when 3-HPA/PCA was used to analyze two mixtures, one containing two 23-mer DNA segments with a 9 Da difference (A and T) and the other with a 7 Da difference (AA and TG), the two 23-mer ion peaks were well separated from each other and an isotopically resolved spectrum of each component was recorded. Under the identical experimental conditions, the sample-to-sample reproducibility, resolution, signal-to-noise ratio and the tolerance to metal salts, with 3-HPA/PCA, were superior to those observed using 3-HPA alone for analysis of DNA segments.     

Chemiluminescence high-performance liquid chromatography for the determination of hyaluronic acid, chondroitin sulphate and dermatan sulphate.

A sensitive chemiluminescence high-performance liquid chromatographic method has been developed for the determination of hyaluronic acid, chondroitin sulphate and dermatan sulphate as their unsaturated disaccharide-dansylhydrazine derivatives involving an effective sample clean-up system. The dansylhydrazones of the unsaturated disaccharides derived from the hyaluronic acid, chondroitin sulphate and dermatan sulphate by chondroitinase ABC and/or chondroitinase ACII, were separated by reversed-phase chromatography using a mixture of 0.1 M sodium acetate buffer (pH 6.0) and 80% acetonitrile on a column (250 mm x 4.0 mm I.D.) packed with amide-80 silica beads (5 microns diameter). For post-column elution in the chemiluminescence system, 1 mM bis[2-(3,6,9-trioxadecanyloxycarbonyl)-4-nitrophenyl]oxalate and 3mM hydrogen peroxide in acetonitrile were used. The detection limit of each glycosaminoglycan was 100 fmol. The method was applicable to the determination of the levels of hyaluronic acid, chondroitin sulphate and dermatan sulphate in rat peritoneal mast cells.     

Improving the Determination of Nitrovin in Feeds by Reversed-Phase LC with SPE

A simple reversed-phase liquid chromatographic method with ultraviolet detector (378 nm) for the determination of nitrovin in feeds was improved and validated. The mobile phase was a mixture of acetonitrile and 0.1% formic acid solution (v/v) in the ratio of 50:50 (v/v), and the flow rate was set at 1.2 mL min^?1. The extraction solution was a mixture of dimethyl formamide, acetonitrile and methanol (50:25:25, v/v), the sample was cleaned-up with reversed-phase solid phase extraction cartridge. The standard nitrovin was purified with crude nitrovin product by ethylene glycol monoethyl ether and identified by elemental analyzer. The limit of detection was 0.05 mg kg^?1 and the limit of quatification was 0.2 mg kg^?1 in feeds. The assay had satisfactory selectivity, recovery, linearity and precise repeatability and trueness.     

Simultaneous LC–MS–MS Determination of Zolmitriptan and Its Active Metabolite N-Desmethylzolmitriptan in Human Plasma

A specific and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method was developed for the determination of zolmitriptan and N-desmethylzolmitriptan in human plasma. The analytes and the internal standard (IS) paroxetine were extracted by liquid–liquid extraction with a mixture of saturated ethyl acetate:dichloromethane (4:1) and were separated using an isocratic mobile phase on a XTerra RP18 column. The mobile phase used was acetonitrile: 5 mM ammonium acetate: formic acid (50:50:0.053, v/v/v). Zolmitriptan and N-desmethylzolmitriptan in a range of 0.25–20 ng mL⁻¹ were easily quantified. The validated method can be applied to pharmacokinetic and bioequivalence studies.

     

High-performance liquid chromatographic method for the determination and pharmacokinetic study of wogonoside in rat serum after oral administration of traditional Chinese medicinal preparation Huang-Lian-Jie-Du decoction

A high-performance liquid chromatographic method for the determination of wogonoside in plasma of rats administrated orally with the traditional Chinese medicinal preparation Huang-Lian-Jie-Du decoction was developed. Sample preparation was carried out by protein precipitation with a mixture of acetonitrile and methanol (1:1, v/v). The extracted sample was separated on a Hypersil C(18) (150 x 5 mm i.d., 5 microm) analytical column by linear gradient elution using 0.05% (v/v) phosphoric acid (containing 5 mm sodium dihydrogen phosphate) and acetonitrile as mobile phase at a flow rate of 1.5 mL/min. The eluate was detected using a UV detector at 276 nm. The assay was linear over the range 0.109-7.0 microg/mL (R(2) = 0.9999, n = 5). Mean recovery was determined as 98.39%. Intra- and inter-day precisions (RSD) were < or =7.59%. The limit of quantitation was 0.109 microg/mL. After validation, the HPLC method developed was applied to investigate the preliminary pharmacokinetics of wogonoside in rat after oral administration of Huang-Lian-Jie-Du decoction.     

高效液相色谱法测定化妆品中黄芩甙

采用高效液相色谱法测定化妆品中黄芩甙含量。样品经乙醇-水(75+25)溶液萃取,用ZORBAX SB C18色谱柱(4.6 mm×25 cm,5μm)分离,用乙腈与磷酸(0.1+99.9)溶液以体积比22比78组成的混合溶液为流动相进行洗脱,在波长276 nm处检测。黄芩甙的质量浓度在100.0 mg.L-1以内与其峰面积呈线性关系,方法的检出限(3S/N)为4.5 mg.kg-1。方法用于化妆品中黄芩甙的测定,加标回收率在76.8%～104.9%之间。     

超高压液相色谱-飞行时间质谱法测定食品中19种非法染料

建立了同时测定食品中19种非法染料的方法。样品经丙酮/正己烷提取后,采用氧化铝柱层析净化,超高压液相色谱C18短柱分离,流动相用乙腈:0.1%甲酸溶液梯度淋洗,采用电喷雾离子源,在正离子模式下以飞行时间质谱检测,质量偏差小于1毫道尔顿。19种非法染料加标回收率在76%～108%,之间,方法的检测限为0.34～14μg/kg,精密度RSD在0.3%～12%之间。     

固相萃取-高效液相色谱-荧光检测土壤中喹诺酮类抗生素

建立了固相萃取-高效液相色谱-荧光(HPLC-FLD)检测土壤中4种喹诺酮类抗生素的分析方法.样品采用50% Mg(NO_3)_2-10% NH_3 · H_2O(96∶ 4,V/V)超声提取,过HLB柱富集净化,再用乙腈-0.067 mol/L H_3PO_4溶液洗脱.采用高效液相色谱-荧光检测器,以乙腈-0.067 mol/L H_3PO_4(用三乙胺调节至pH 2.5)为流动相,于激发波长280 nm、发射波长450 nm处进行检测.土壤样品中4种喹诺酮类抗生素的加标回收率在60.4%～99.3%之间,检出限为0.58～1.0 μg/kg.对蔬菜基地土壤样品分析结果表明,本方法能够满足实际样品的分析要求,4种喹诺酮类抗生素均被检出,土壤中抗生素污染问题值得关注.     

Micellar electrokinetic chromatography of charged and neutral drugs in acidic running buffers containing a zwitterionic surfactant, sulfonic acids or sodium dodecyl sulphate separation of heroin, basic by-products and adulterants

A procedure for the separation of charged and neutral solutes in acidic micellar running buffers has been developed. The procedure is based on a zwitterionic surfactant 3-N,N-dimethylmyristylammoniopropanesulfonate (MAPS) and alkylsulfonates added to the running buffer at pH 4.0. The alkylsulfonates increase the migration-time window for elution of neutral substances by increasing electro-osmotic mobility and by creating a negative micellar electrophoretic mobility. The test solution contained opiates and adulterants found in heroin seizures. Both the test solution and actual heroin seizures were successfully separated using a running buffer containing 50 mM 6-aminocaproic acid adjusted to pH 4.0 with 50 mM MAPS, 5 mM 1-heptanesulfonic acid and 10% acetonitrile. The procedure offers an alternative to micellar electrokinetic chromatographic separations based on charged surfactants in alkaline buffers.