1,2-萘醌-4-磺酸钠测定盐酸吡硫醇的研究

建立了1,2-萘醌-4-磺酸钠分光光度法测定含羟基药物盐酸吡硫醇的方法.研究表明,在pH=13.00的KCl-NaOH缓冲溶液中,盐酸吡硫醇能够催化氢氧根离子与1,2-萘醌-4-磺酸钠反应形成橙红色的2-羟基-1,4-萘醌,其最大吸收波长为454nm.盐酸吡硫醇浓度在3.2μg/mL～80μg/mL范围内与吸光度呈现良好的线性关系.线性回归方程为A＝0.02715+0.02837C(×105 mol/L),线性相关系数r＝0.9986.表观摩尔吸光系数、相对标准偏差(R.S.D.)和检测限分别为2.84×103L/mol/cm、1.6%和2.0μg/mL.通过对片剂中的盐酸吡硫醇含量进行测定,回收率在98%～101%.     

Spectrophotometric determination of cefotaxime by using sodium 1,2-naphthoquinone-4-sulfonate

A novel method is established to determine cefotaxime by using sodium 1,2-naphthoquinone-4-sulfonate (NQS) as a chromogenic reagent. A russety product can be formed owing to the nucleophilic substitution reaction between cefotaxime and NQS in 0.1 M solution of NaOH. The maximal absorption wavelength of the product is 489 nm. Absorbance is linear with the concentration of cefotaxime in the range of 3.8–114.6 mg/L, and the regression equation is A = 0.04481 + 0.00567c (mg/L), with a correlation coefficient of 0.9992. The detection limit and the RSD are 3 mg/L and 1.2%, respectively. The average recovery is in the range of 98.9–101.2%. The results indicate that the method could be applied to the determination of cefotaxime in injection.     

1,2-萘醌-4-磺酸钠体系分光光度法测定头孢他啶

建立了用1,2-萘醌-4-磺酸钠(NQS)作为显色剂分光光度法测定头孢他啶(ceftazidime)的新方法.在pH 13.0缓冲溶液中,NQS能直接与头孢他啶发生亲核取代反应生成红褐色化合物,其最大吸收波长为484 nm.头孢他啶在2.98～127.3 mg/L浓度范围内与吸光度呈良好线性关系,线性回归方程A=0.0...     

1，2-萘醌-4-磺酸钠分光光度法测定链霉素的研究

链霉素(streptomycin,STR)是一种对结核分枝杆菌有强大抗菌作用的氨基糖苷类抗生素,它通过作用于细胞的核糖体抑制细菌蛋白质的生物合成而呈现杀菌作用[1].目前所报道检测链霉素含量的方法主要有高效液相色谱法[2] 、鲁米诺的流动注射化学发光法[3] 、微生物学检测法[4、5] 、荧光法[6]、免疫法[7]以及紫外分光度度法[8]等,但以可见光度法测定链霉素的研究还很少有报道.本文基于1,2-萘醌-4-磺酸钠(NQS)能与含有胺基类药物分子结构中的胺基发生亲核缩合或取代作用 [9-13],建立了以NQS作为显色剂在可见光度法测定STR的新方法.研究表明,控制溶液pH12.00,STR与NQS发生缩合反应生成摩尔比为1: 2红褐色产物,最大吸收波长λ max =470 nm,STR浓度在2.91μg/mL～145.7μg/mL范围内与吸光度成良好线性关系.与文献中所报道的其他方法相比,该方法不仅具有简便、快速、不需昂贵的仪器设备等特点,具有重要的应用价值.     

Liquid chromatographic determination of aniline and derivatives in environmental waters at nanogram per litre levels using fluorescamine pre-column derivatization

Summary Fluorescamine (fluram) has been used as a fluorogenic compound for pre-column derivatization of aniline and some derivatives. Anilines were derivatized with fluram in citrate buffer media (pH 5.5) to form pyrrolinones. The highly fluorescence pyrrolinones were isolated and pre-concentrated by solid phase extraction. A reversed phase, Spherisorb RP-8 column and tetrahydrofuran: water:formic acid (42:56:2) mobile phase was used for separation. Detection method was by a sensitive fluorimetric method and quantitation was at 395 and 495 nm. The various parameters such as reaction conditions between anilines and fluram, solid phase extraction and chromatographic separation were optimized. Calibrations were linear over the range considered with excellent correlation coefficients (r>0.999). Relative standard deviations are less than 2.5 % and detection limits for aniline,p-toluidine, 4-chloroaniline and 4-bromoaniline were 6, 30, 6 and 8 ng L⁻¹, respectively. This method has been used successfully for the determination of anilines in environmental waters.     

1, 2-萘醌-4-磺酸钠分光光度法测定间苯二酚

在pH 13.00缓冲溶液中, 间苯二酚能够催化氢氧根离子与1,2-萘醌-4-磺酸钠反应生成2-羟基-1, 4-萘醌, 其最大吸收波长为454 nm. 间苯二酚质量浓度在0.39～13.21 mg/L范围内与吸光度呈现良好线性关系. 线性回归方程为A=0.01918+0.05703c (×105 mol/L), 相关系数r=0.9981. RSD和检测限分别为1.6%, 0.34 mg/L (3σ/k). 该法能够直接用于水样中间苯二酚含量测定, 回收率在94.3%～106%.     

1,2-萘醌-4-磺酸钠试剂分光光度法测定葡萄糖

建立了用1, 2-萘醌-4-磺酸钠测定葡萄糖的新方法. 研究表明, 在pH 13.00的缓冲溶液中, 葡萄糖能够催化1,2-萘醌-4-磺酸钠与OH-反应生成2-羟基-1, 4-萘醌, 其最大吸收波长为454 nm. 葡萄糖质量浓度在0.8～80 mg/L范围内, 呈现良好线性关系. 线性回归方程为A＝0.0165+0.01004c(10-5 mol/L), 线性相关系数r＝0.9985. RSD和检出限分别为0.92%, 0.7 mg/L. 该法能够直接用于注射液中葡萄糖含量的测定.     

Liquid chromatographic method for the determination of calcium cyanamide using pre-column derivatization.

A specific and stability-indicating high-performance liquid chromatographic (HPLC) method has been developed for the analysis of calcium cyanamide in bulk material and dosage form. Calcium cyanamide in samples was converted into dansyl cyanamide. A muBondapak C18 column was employed for HPLC with 0.01 M sodium phosphate (pH 6.3)-acetonitrile (75:25, v/v) as the mobile phase. The proposed HPLC method was validated for linearity, specificity, accuracy and reproducibility.     

1,2-萘醌-4-磺酸钠作为显色剂分光光度法测定阿魏酸哌嗪

建立了用1,2-萘醌-4-磺酸钠测定阿魏酸哌嗪的新方法.在pH 13.0的KCl-NaoH缓冲溶液中,阿魏酸哌嗪与1,2-萘醌-4-磺酸钠反应形成红褐色产物,其最大吸收波长为484 nm.阿魏酸哌嗪浓度在0.4～80μg/mL范围内呈现良好线性关系.线性回归方程为A=0.07742+0.01216ρ(μg/mL),线性相关系数r=0.9986,表观摩尔吸光系数5.8×103 L/mol/cm,相对标准偏差(RSD)和检出限分别为0.84%和0.29μg/mL.对药物样品中阿魏酸哌嗪的含量进行测定,平均回收率在95.1%～103.3%.     

Strategies for in-capillary derivatization of amino acids in capillary electrophoresis using 1,2-naphthoquinone-4-sulfonate as a labeling reagent.

This paper examines the potentiality of in-capillary derivatization for improving the sensitivity of the spectrophotometric detection of amino acids in capillary zone electrophoresis. 1,2-Naphthoquinone-4-sulfonate was selected as the labeling agent of amino acids. The underivatized sample and the reagent solution segments are injected by pressure into the capillary prior to applying the running voltage. The corresponding derivatization reaction occurs inside the capillary once the potential is applied, as it induces mixing of the sample with the reagent. Several introduction modes consisting of tandem or sandwich configuration have been evaluated. These techniques result in a straightforward and automated way of carrying out a derivatization. Furthermore, in-capillary procedures may become much more attractive than conventional pre-capillary derivatization in terms of sensitivity and reproducibility. The optimum operation mode found consists of a sandwich system where the sample is injected in between two reagent segments. The method was applied to the determination of amino acids in feed samples. Results show a good concordance with those given by a standard amino acid analyzer.     

Liquid chromatographic determination of nitroaromatics in water following solid phase extraction,pre-column reduction and derivatization

Summary A selective and sensitive method for determination of nitroaromatics is described. The analytes were reduced to corresponding primary amines with iron powder and then derivatized with fluram in citrate buffer to form pyrrolinones. The highly fluorescent pyrrolinones were isolated and preconcentrated by octadecylsilane solid phase extraction cartridge followed by reversed-phase, high-performance liquid chromatographic analysis. Detection was at 395–495 nm. Various aspects such as the reduction process, derivatization, solid phase extraction and chromatographic separation were optimized. Analysis time was relatively short due to a special design for successive reduction and preconcentration. Limits of detection for 3-nitrophenol, nitrobenzene, 4 and 2-nitrotoluene were less than 60, 12, 60 and 280 ng L^–1 respectively.     

Spectrophotometric determination of aminomethylbenzoic acid using sodium 1,2-naphthoquinone-4-sulfonate as the chemical derivative chromogenic reagent

A new method has been established for the determination of aminomethylbenzoic acid using sodium 1,2-naphthoquinone-4-sulfonate as the chemical derivative chromogenic reagent. This method is based on the formation of a pink compound from the reaction of aminomethylbenzoic acid and sodium 1,2-naphthoquinone-4-sulfonate. The nucleophilic substitution reaction proceeds quantitatively in pH 12.0 buffer solution. The stoichiometric ratio of the reaction, maximum absorption wavelength and the value of epsilon(430) were 1:1, 430 nm, and 2.87 x 10(3)L mol(-1)cm(-1), respectively. Beer's law was obeyed in the range of 0.80-80 mg/L of aminomethylbenzoic acid. The data have been filled to a linear regression equation A=0.03183+0.01658C (mg/L), with a correlation coefficient of 0.9996. The detection limit is 0.11 mg/L, R.S.D. is 0.54%, and average recovery is over 99.6%. This paper further improves the determination of aminomethylbenzoic acid compared to the previous methods. The kinetic property and reaction mechanism have also been discussed. This proposed method has been successfully applied to the determination of aminomethylbenzoic acid in injection of aminomethylbenzoic acid with satisfactory results.     

Novel spectrophotometric method for determination of cinacalcet hydrochloride in its tablets via derivatization with 1,2-naphthoquinone-4-sulphonate

This study represents the first report on the development of a novel spectrophotometric method for determination of cinacalcet hydrochloride (CIN) in its tablet dosage forms. Studies were carried out to investigate the reaction between CIN and 1,2-naphthoquinone-4-sulphonate (NQS) reagent. In alkaline medium (pH 8.5), an orange red-colored product exhibiting maximum absorption peak (λ _max) at 490 nm was produced. The stoichiometry and kinetic of the reaction were investigated and the reaction mechanism was postulated. This color-developing reaction was employed in the development of a simple and rapid visible-spectrophotometric method for determination of CIN in its tablets. Under the optimized reaction conditions, Beer's law correlating the absorbance with CIN concentration was obeyed in the range of 3 - 100 μg/ml with good correlation coefficient (0.9993). The molar absorptivity (ε) was 4.2 × 10⁵ l/mol/cm. The limits of detection and quantification were 1.9 and 5.7 μg/ml, respectively. The precision of the method was satisfactory; the values of relative standard deviations (RSD) did not exceed 2%. No interference was observed from the excipients that are present in the tablets. The proposed method was applied successfully for the determination of CIN in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was 100.80 - 102.23 ± 1.27 - 1.62%. The results were compared favorably with those of a reference pre-validated method. The method is practical and valuable in terms of its routine application in quality control laboratories.     

1,2-Diarylethylenediamines as pre-column fluorescence derivatization reagents in high-performance liquid chromatographic determination of catecholamines in urine and plasma

Meso- and dl-1,2-diarylethylenediamines (14 species) were evaluated for pre-column fluorescence derivatization reagents in the high-performance liquid chromatographic determination of catecholamines (norepinephrine, epinephrine and dopamine) in human urine and plasma. Of the compounds, meso-1,2-bis(4-methoxyphenyl)ethylenediamine was most preferable for all the catecholamines in terms of sensitivity and selectivity. The detection limit for each catecholamine is approximately 0.5 fmol in a 50-microliters injection volume.     

Liquid chromatographic determination of dicarboxylic acids based on intramolecular excimer-forming fluorescence derivatization

A highly sensitive and selective fluorimetric determination method for dicarboxylic acids (C5-C12) has been developed. This method is based on an intramolecular excimer-forming fluorescence derivatization with a pyrene reagent, 4-(1-pyrene)butyric acid hydrazide (PBH), followed by reversed-phase liquid chromatography (LC). The carboxylic acids were converted to the corresponding dipyrene-labeled derivatives by reaction with PBH in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. The derivatives afforded intramolecular excimer fluorescence (450-550 nm) which can clearly be discriminated from the normal fluorescence (370-420 nm) emitted from PBH and monopyrene-labeled derivatives of monocarboxylic acids. The structures of the derivatives and the emission of excimer fluorescence were studied by LC with mass spectrometry and with spectrofluorimetry, respectively. The PBH derivatives of the carboxylic acids could be separated by reversed-phase LC on an ODS column with isocratic elution. The detection limits (signal-to-noise ratio = 3) were 1.3 fmol to undetectable for a 20-microl injection.     

Liquid chromatographic determination of microcystins in water samples following pre-column excimer fluorescence derivatization with 4-(1-pyrene)butanoic acid hydrazide

A method to measure the concentrations of microcystins (MCs) in water samples has been developed by incorporating pre-column fluorescence derivatization and liquid chromatography (LC). A solid-phase extraction for pretreatment was used to extract the MCs in water samples. The MCs were derivatized with excimer-forming 4-(1-pyrene)butanoic acid hydrazide (PBH). The MCs could then be detected by fluorescence after separation with a pentafluorophenyl (PFP)-modified superficially porous (core shell) particle LC column. The derivatization reactions of MCs with PBH proceeded easily in the presence of 4,6-dimethoxy-1,3,5-triazin-2-yl-4-methylmorpholinium (DMT-MM) as a condensation reagent, and the resulting derivatives could be easily separated on the PFP column. The derivatives were selectively detected at excimer fluorescence wavelengths (440–540 nm). The instrument detection limit and the instrument quantification limit of the MCs standards were 0.4–1.2 μg L⁻¹ and 1.4–3.9 μg L⁻¹, respectively. The method was validated at 0.1 and 1.0 μg L⁻¹ levels in tap and pond water samples, and the recovery of MCs was between 67 and 101% with a relative standard deviation of 11%. The proposed method can be used to quantify trace amounts of MCs in water samples.     

氯化十四烷基二甲基苄基铵对羧甲司坦和1,2-萘醌-4-磺酸钠反应的增敏作用及羧甲司坦的测定

本文建立了一种用1,2-萘醌-4-磺酸钠测定羧甲司坦的新方法。研究表明：控制溶液pH11.00,羧甲司坦,1,2-萘醌-4-磺酸钠与氯化十四烷基二甲基苄基铵反应生成摩尔比为1:1:1红褐色产物,λ max = 466nm,线性方程为;A =0.22302+0.01198 C(mg/L),线性相关系数r = 0.9992, 表观摩尔吸光系数ε＝2.2 ×103 L•mol-1cm-1。羧甲司坦浓度在0.72～28.67mg/L内成良好线性关系,R.S.D.和检测限分别为 0.52%和0.70µg/mL,平均回收率为99.0﹪～103﹪。该法能够直接用于药物样品中羧甲司坦的测定,结果满意。     

Catalysis reaction between sodium 1,2-naphthoquinone-4-sulfonate and hydroxyl ion using captopril as catalyzer and determination of captopril

A novel and simple spectrophotometric method for the determination of Captopril with sodium 1,2-naphthoquinone-4-sulfonate is established in this paper. The detailed reaction mechanism is proposed and discussed. It is based on the fact that captopril can catalyze the reaction between sodium 1,2-naphthoquinone-4-sulfonate and hydroxyl ion to form 2-hydroxy-1,4-naphthoquinone in buffer solution of pH 13.00. Beer's law is obeyed in a range of 0.64-80 μg mL⁻¹ at the maximal absorption wavelength of 442 nm. The equation of linear regression is A = 0.05815 + 0.00589C (μg mL⁻¹), with a linear regression correlation coefficient of 0.9981. The detection limit is 0.3 μg mL⁻¹, R.S.D. is 0.77% and the recovery rate is in range of 96.0-103.8%. Furthermore, the method has been validated and successfully applied to the determination of captopril in pharmaceutical samples.     

High performance liquid chromatographic determination of N-nitrosoamines by pre-column fluorescence derivatization with acridone-N-acetyl chloride

A sensitive high performance liquid chromatographic method for the determination of N-nitrosoamines with pre-column fluorescence derivatization has been developed. N-nitrosoamines are first changed into secondary amines using denitrosation reagent, then react with acridone-N-acetyl chloride (ARC-Cl) to produce corresponding secondary amine derivatives, which exhibit a strong fluorescence. Maximum emission for ARC derivatives is 430 nm (lambda(ex) 404 nm). The labelled derivatives are very stable, less than 4% decomposition occurs after heating at 40 degrees C for 24 h. Fluorescence intensities of derivatives are higher in neutral and alkaline than in acidic solutions. This method, in conjunction with a multi-gradient program, offers a baseline resolution of the ARC derivatives from a linear acetonitrile gradient. Separation is carried out on a reverse phase C(18) column. Derivatization and chromatographic conditions are optimized. The relative standard deviation (n=6) at an analytical concentration of 10 pmol of each N-nitroamine is less than 4.5%. The detection limits at the fmol level. The method described is also suitable for analysis of other amino compounds in different biological samples.