Application of sugaring-out extraction for the determination of sulfonamides in honey by high-performance liquid chromatography with fluorescence detection

A simple sugaring-out assisted liquid-liquid extraction method combined with high-performance liquid-chromatography with fluorescence detection (HPLC-FL) was developed for the extraction and determination of sulfonamides in honey. Sample preparation consisted of acid hydrolysis to release sugar-bound sulfonamides. After derivatization with fluorescamine, the derivatives were partitioned into the organic layer under the honey (sugar)/water/acetonitrile system. The clear organic extract obtained by centrifugation could be injected into the HPLC system either directly or after dilution. Linearity was obtained with the coefficient of determination (R(2)) higher than 0.998 from 2 to 200 ng/mL. Under the optimal conditions, recoveries were determined for honey fortified at three levels (5, 20, and 100 ng/g) were 80.9-99.6% with coefficients of variation of 0.3-4.4%. Limits of detection for the sulfonamides studied were found to range from 0.6 to 0.9 ng/g.     

尿中氯硝西泮代谢物7-氨基氯硝西泮的薄层色谱检测法

采用高效薄层色谱法检测尿中氯硝西泮代谢物7－氨基氯硝西泮（7ACLZ），分析物斑点用弗路兰进行荧光显现，灵敏度高，检出限5μg/L，定量下限15μg/L，可以检测人口服2mg氯硝西泮后48h内排泄尿的7ACLZ,适用于麻醉抢劫犯罪案件中药物检测。     

Derivatisation of sympathomimetics with primary amino groups on thin-layer plates by spotting the sample spots with fluorescamine

Summary A method has been developed for the quantitative determination of sympathomimetics containing a primary amino group on thin-layer plates with fluorescamine. The reaction is carried out by spotting fluorescamine solution in acetone on top of the sample spots. The fluorescamine derivatives are subsequently separated using appropriate solvent systems. Spotting a buffer before reaction and spraying with triethanolamine after development is unnecessary. The consumption of reagent is extremely low. For ten thin-layer plates with ten sample spots per plate only 0.2 cm³ reagent solution are needed. The method has been applied to the quantitative determination of some compounds with primary amino groups in pharmaceutical preparations.Dedicated to Prof. Dr. G. Zigeuner on his 60^th birthday.     

荧光衍生化法测定牛奶中氯霉素残留的研究

研究氯霉素荧光衍生化反应的实验条件，建立荧光分光光度法测定牛奶中氯霉素残留的新方法。牛奶中的氯霉素，用乙酸乙酯超声提取3次，浓缩，盐水溶解，正己烷脱脂，再经乙酸乙酯反萃取，氮气吹干，经还原，用荧光胺衍生化测定。氯霉素衍生化产物质量浓度在12．5～500ng／mL范围内，相对荧光强度与质量浓度关系为F=1．44 0.1424ρ，r^2=0．9998。加标回收率为81％～87％，相对标准偏差为3．9％～8．4％。本方法牛奶中氯霉素可达2．5ng/mL。     

Determination of Sulfadiazine Based on Its Derivatization with Fluorescamine by Self-Ordered Ring Fluorescence Microscopic Imaging Technique

A self-ordered ring (SOR) fluorescence microscopic imaging technique has been developed for the determination of trace amounts of sulfadiazine based on its derivatization with fluorescamine. In the presence of HAc-NaAc buffer solution (pH 3.12) and polyvinyl alcohol-124 (PVA-124), the droplet containing fluorescamine derivatized sulfadiazine can form a SOR on the solid support after solvent evaporation with the diameter of 1.86 mm and its ring belt width of 54.9 μm. The quantitative analysis of sulfadiazine is achieved with the linear range of 7.8×10-14～1.8×10-12 mol·ring-1 (3.9×10-7～9.0×10-6 mol·L-1) and detection limit of 7.8×10-15 mol·ring-1 (3.9×10-8 mol·L-1) when 0.2 μL droplet was spotted. The technique has been satisfactorily applied to the determination of sulfadiazine in the tablet, synthetic sample and residues in six different milk samples with the recoveries of 91.0%～105.8%, respectively, and RSDs less than 4.4%.     

Simple and Sensitive Spectrofluorimetric Method for the Determination of Oseltamivir Phosphate in Capsules Through Derivatization with Fluorescamine

A new, simple and sensitive spectrofluorimetric method has been developed for the determination of oseltamivir phosphate (OSP) in capsules. The method is based on the reaction between oseltamivir and fluorescamine in borate buffer solution of pH 8.50 to give highly fluorescent derivatives that are measured at 483 nm using an excitation wavelength of 381. The different experimental parameters effecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence intensity concentration plot is rectilinear over the range 50–450 ng mL⁻¹ with a lower detection limit (LOD) of 1.219 ng mL⁻¹ and limit of quantitation (LOQ) of 4.064 ng mL⁻¹. Selectivity was validated by subjecting stock solution of OSP to acidic, basic, oxidative, and thermal degradation. No interference was observed from excipients present in formulations. The developed method was successfully applied to determination of the drug in capsules. The mean % recovery (n = 6) was 100.08. The results obtained were in good agreement with those obtained using a reported spectrophotometric method.     

A Spectrofluorimetric Sequential Injection Method for the Determination of Penicillamine Using Fluorescamine in the Presence of β-cyclodextrins

A simple, robust and sensitive sequential injection spectrofluorimetric method for the determination of penicillamine (PA) in pharmaceutical formulations is developed. The method is based on the formation of a highly fluorescent derivative when penicillamine is reacted with fluorescamine (FL) in borate buffer of pH 9.3. The derivative produced is monitored at an emission wavelength of 495 nm using an excitation wavelength of 355 nm. The optimum conditions for the determination of PA with FL were: 3 mM FL, pH 9.3, 5 mM methyl-β-cyclodextrin, sample volume of 75 μL and reagent volume of 75 μL. Furthermore, the effect of various media on the fluorescence intensity of the PA–FL derivative was studied and methyl-β-cyclodextrin was found to give the largest enhancement. A linear dynamic range for the determination of PA of 5–80 ppm was obtained with a sampling frequency of 50 h⁻¹ and a relative standard deviation of less than 2.5%. The method was applied to the determination of PA in pharmaceutical formulations with reasonable recoveries ranging from 101.0–103.1%, indicating that no interference is observed from concomitants usually present in dosage forms.     

Spectrofluorimetric Evaluation of Total Aliphatic and Aromatic Amines in Well Waters and Wastewaters

Abstract

A simple and rapid spectrofluorimetric method is described for the determination of aliphatic and aromatic amines on the basis of ammonia and aniline, respectively. Aromatic amines in samples were reacted at pH 5.5 with fluram immoblised on an Octadecylsilane Solid Phase Extraction (ODS-SPE) cartridge. The produced pyrrolinones were adsorbed on SPE and separated from the aliphatic amines. Analysis of these compounds was carried out by elution of SPE with 1 ml Tetrahydrofuran (THF) and determination of fluorescence intensity at excitation wavelength 400 nm and emission wavelength 475 nm. Aliphatic amines after passing from SPE were collected and reacted with fluram at pH 9.2, and extracted into dichloromethane at pH 3 and quantitated fluorimetrically.

Linear dynamic ranges and detection limits (LOD) were 1–20, 0.43 mg 1^?1 and 1-200, 0.39 μg 1^?1 for ammonia and aniline, respectively. The proposed method was successfuly applied for the evaluation of these compounds in local well waters and municipality wastewaters.     

Derivatizat Ion of Primary Aromatic Amines with Fluorescamine

Abstract

Fluorescamine forms stable, fluorescent derivatives with sterically-unhindered primary aromatic amines in both aqueous (borate buffer, pH 9/acetonitrile) and nonaqueous (pyridine/-acetonitrile) media. Aromatic amines with a substituent such as a methyl group or an aromatic ring ortho to the amine functionality either derivatized poorly or not at all because of steric hindrance.     

Determination of 1-aminocyclopropane-1-carboxylic Acid in Apple and Peach Extracts by High Performance Liquid Chromatography Coupled to a Fluorescence Detector

A new, sensitive, and simple HPLC method was described for the determination of 1-aminocyclopropane-1-carboxylic acid (ACC) in apple and peach extracts. The method was based on the derivatization of ACC with fluorescamine in borate buffer systems of pH 8.0 to yield a highly fluorescent product. The experimental parameters affecting the derivatization reaction efficiency were optimized by fluorimetric analysis. Under optimum derivatization conditions, the derivative product of ACC in apple and peach extracts without extra purification was successfully chromatographed on a C-18 column by HPLC coupled to fluorescence detection. The derivative product of ACC with fluorescamine could be well separated from other concomitant substances or their derivatives that might interfere with the determination of ACC. The linearity of ACC was measured in the range of 23.82–238.82 µg · L^?1 with a good correlation coefficient of 0.9997. Based on signal-to-noise ratio of 3, a low detection limit of 5.0 µg · L^?1 could be reached. The proposed method was applied successfully to the determination of ACC in the crude apple and peach extracts without extra purification with low RSDs of 0.19–1.9% and good recoveries of 90.89–104.4%. The sensitive HPLC quantitative method is of great significance for the investigations of ACC metabolism in plants.