Serotonin and its N-Acetylated and Acidic Derivatives in Insect Brain as Determined by High-Performance Liquid Chromatography with Electrochemical Detection

1993 ◽  
Vol 28 (1) ◽  
pp. 16-24 ◽  
Author(s):  
R. Vieira ◽  
M. Aldegunde
Keyword(s):  
Analytical Method ◽  
High Performance ◽  
Amperometric Detection ◽  
High Sensitivity ◽  
Hplc Method ◽  
Insect Brain ◽  
Oxidative Deamination ◽  
Wide Range ◽  
Hydrodynamic Voltammetry

The determination of serotonin (5-HT), N-acetylserotonin (NAS) and 5-hydroxy-3-indoleacetic acid (5-HIAA) in single brains of two acridids (Paracinema tricolor and Oedipoda caerulescens) was accomplished using a HPLC method combined with amperometric detection. A hydrodynamic voltammetry approach was used to assess the identity of each peak by comparing the voltammograms of standards and those of samples. The analytical method gave satisfactory reproducibility and sensitivity, and detected levels of 5-HT, NAS and 5-HIAA as low as 29, 55 and 10 fmol, respectively. This high sensitivity together with the simplicity of sample processing make the present analytical method suitable for a wide range of studies concerning indoleamine analyses in the insect nervous system. In both acridids, 5-HT showed the largest quantities, while its derivatives occurred in extremely low amounts. The results suggest that N-acetylation of 5-HT is quantitatively preferred to oxidative deamination in both species (NAS levels were 4-fold those of 5-HIAA). The relative importance of each catabolic pathway is discussed as related to physiological and genetic aspects.

Determination of Selected Phthalates in Some Commercial Cosmetic Products by HPLC-UV

2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural
Keyword(s):  
High Performance ◽  
Phthalate Esters ◽  
High Sensitivity ◽  
Hplc Method ◽  
Cosmetic Products ◽  
Limit Of Quantification ◽  
Nail Polish ◽  
Accuracy And Precision ◽  
Butyl Phthalate

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.

scholarly journals ANALYTICAL METHOD DEVELOPMENT AND VALIDATION OF ATOMOXETINE HYDROCHLORIDE USING RAPID HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC TECHNIQUE

2018 ◽  
Vol 11 (11) ◽  
pp. 118
Author(s):  
Zubaidur Rahman ◽  
Vijey Aanandhi M ◽  
Sumithra M
Keyword(s):  
High Performance ◽  
Method Development ◽  
High Sensitivity ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Chromatographic Technique ◽  
Pharmaceutical Dosage Form ◽  
Rp Hplc ◽  
Liquid Chromatographic

Objective: A simple, novel, sensitive, rapid high-performance liquid chromatographic (RP-HPLC) method has been developed and validated for quantitative determination of atomoxetine HCl (ATH) in bulk and formulations.Methods: The chromatographic development was carried out on RP-HPLC. The column used as Xterra RP 18 (250 mm × 4.6 mm, 5 μ particle size), with mobile phase consisting of methanol: water 80:20 V/V. The flow rate was 1.0 mL/min and the effluents were monitored at 270 nm.Results: The retention time was found to be 5.350 min. The method was validated as per International Conference on Harmonization Guideline with respect to linearity, accuracy, precision, and robustness. The calibration curve was found to be linear over a range of 2–10 μg/mL with a regression coefficient of 0.9999. The method has proved high sensitivity and specificity.Conclusion: The results of the study showed that the proposed RP-HPLC method was simple, rapid, precise and accurate which is useful for the routine determination of ATH in bulk drug and in its pharmaceutical dosage form.

scholarly journals Simultaneous Determination of Eight Synthetic Permitted and Five Commonly Encountered Nonpermitted Food Colors in Various Food Matrixes by High-Performance Liquid Chromatography

2010 ◽  
Vol 93 (5) ◽  
pp. 1503-1514 ◽  
Author(s):  
Sumita Dixit ◽  
Subhash K Khanna ◽  
Mukul Das
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
High Sensitivity ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Hplc Method ◽  
Food Category ◽  
Food Commodities ◽  
Food Colors

Abstract A simple and sensitive HPLC method has been developed for the simultaneous determination of eight permitted food colors and five commonly encountered nonpermitted colors in various food commodities, including sugar-, fat-, and starch-based food matrixes. The method uses a specific food category-based cleanup/treatment procedure before color extraction to avoid the interference of food matrixes, and to obtain the optimal color extraction. Analysis was performed on a reversed-phase C18 -Bondapak column with ammonium acetate and acetonitrile gradient elution as the mobile phase; a programmable max-specific visible detection was used to monitor colors to obtain the higher sensitivity and expanded scope needed for multicolor blends having diverse absorption maxima. All colors showed good linearity, with regression coefficients of 0.99740.9999. The LOD and LOQ values ranged from 0.01 to 0.12 mg/L, and from 0.04 to 0.83 mg/L or mg/kg, respectively. The intraday and interday precision tests produced good RSD values, and the recoveries from different food matrixes ranged from 82 to 104%. The method offers high sensitivity for analysis of a wide variety of food matrixes containing a broad scope of multicolor blends. Two nonpermitted colors, orange II and metanil yellow, were found. Also, a number of samples contained permitted colors at levels two-to seven-fold higher than those prescribed.

scholarly journals Chromatographic Methods for the Determination of Aminexil, Pyridoxine, and Niacinamide in a Novel Cosmetic Hair Preparation

2020 ◽  
Vol 103 (4) ◽  
pp. 1167-1172
Author(s):  
Mamdouh R Rezk ◽  
Hebatallah M Essam ◽  
Enas A Amer ◽  
Dina M S Youssif
Keyword(s):  
High Performance ◽  
High Sensitivity ◽  
Ammonia Solution ◽  
Hplc Method ◽  
The Novel ◽  
Chromatographic Methods ◽  
Ich Guidelines ◽  
Sensitivity And Selectivity ◽  
Keratin Fibers

Abstract Background Aminexil, a new compound patented by L’Oreal, has a stimulating effect on human keratin fibers. Pyridoxine HCl and niacinamide are added to boost the hair tonic effect of aminexil. Objective Two novel chromatographic methods were developed for the determination of aminexil (AX), niacinamide (NA) and pyridoxine HCl (PD) in the novel hair tonic preparation. Methods The developed methods were high-performance liquid chromatography (HPLC) and thin layer chromatography (TLC) with densitometric determination. Different experimental parameters were investigated and optimized to achieve complete baseline separation and well resolved peaks. The RP-HPLC separation was achieved using a Thermoscientific BDS hypersil C18 (250 × 4.6 mm, 5 µm) column using 0.005 M hexane sulfonic acid: methanol (80: 20, v/v) as a mobile phase. For the TLC method, the three analytes were partitioned between propanol: toluene: ammonia solution (40:60:2, v/v/v) and fluorescent silica plates. The two methods were validated in compliance with International Conference on Harmonization (ICH) guidelines. The obtained data were statistically analyzed to confirm the existing results. The developed methods were successfully applied for determination of the studied drugs in pure forms and in the cosmetic preparation. Results For the HPLC method, the RSDs of AX, NA and PD were 0.70, 0.88 and 1.17 respectively. For the TLC method, the RSDs of AX, NA and PD were 1.06, 1.37 and 0.73 respectively. Conclusions The proposed chromatographic methods showed high sensitivity and selectivity for the three compounds under analysis in the laboratory prepared mixture and in the hair tonic preparation. Highlights Aminexil, Pyridoxine, Niacinamide, HPLC. The present work offers two reproducible, accurate, validated, time and cost saving alternatives for the quantitative and qualitative determination of medicated hair preparation.

Evaluation of intraocular penetration of levofloxacin by high performance liquid chromatography

2021 ◽  
Vol 2 (3) ◽  
pp. 155-158
Author(s):  
Mahsa Hasanzadeh ◽  
◽  
Amir Heydari ◽  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Cataract Surgery ◽  
High Performance ◽  
Topical Administration ◽  
Hplc Method ◽  
Fluorescence Detector ◽  
Wide Range ◽  
The Mean

AIM: To evaluate the levofloxacin eye drop into human eye penetration, levofloxacin eye drop concentrations in human ocular aqueous of 33 patients undergoing cataract surgery were measured by high performance liquid chromatography (HPLC). METHODS: Totally 33 volunteer patients who scheduled for phacoemulsification surgery received one drop of levofloxacin every 6h for 3d before and on the day of surgery, administration of drug was stopped 1h before surgery. Levofloxacin concentration in aqueous humor was measured by HPLC method with fluorescence detector. RESULTS: A simple, effective and sensitive HPLC method for determination of levofloxacin in human ocular aqueous was validated. Linearity was shown for levofloxacin concentration over a wide range of 1.95×10-3-1.50 µg/mL. The mean aqueous level of levofloxacin was 0.3399±0.03405 µg/mL. CONCLUSION: Results from the present study demonstrate that topical administration of levofloxacin 0.5% before cataract surgery with routine dose (one drop every 6h) unable to reach MIC90 for most common microorganism causing acute bacterial endophthalmitis.

scholarly journals Development and Validation of an Analytical Method Based on HPLC-ELSD for the Simultaneous Determination of Rosmarinic Acid, Carnosol, Carnosic Acid, Oleanolic Acid and Ursolic Acid in Rosemary

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 323 ◽  
Author(s):  
Penghui Li ◽  
Ailing Liu ◽  
Yinhua Li ◽  
Bin Yuan ◽  
Wenjun Xiao ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Ursolic Acid ◽  
Oleanolic Acid ◽  
Analytical Method ◽  
Rosmarinic Acid ◽  
High Performance ◽  
High Sensitivity ◽  
Carnosic Acid ◽  
Effective Manner

The safety, efficacy and stability of natural antioxidants have been the focus of research in the food industry, with the aim of rapidly analyzing and controlling the quality of rosemary and its extracts, a novel analytical method involving high-performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous determination of rosmarinic acid, carnosol, carnosic acid, oleanolic acid and ursolic acid in rosemary. Chromatographic separation was conducted with gradient elution mode by using a Zorbax SB-C18 column (4.6 mm × 250 mm, 5 μm) with mobile phases of methanol and 0.6% acetic acid. The drift tube temperature of ELSD was 70 °C, and the pressure of nebulizer nitrogen gas was 40 Psi. The method developed has high sensitivity (with limits of detection from 1.3 to 8.6 μg/mL), acceptable linearity over the tested concentrations (with correlation coefficients from 0.991 to 0.999), good repeatability (with intra- and inter-day CV less than 3.1% for all analytes) and satisfactory accuracy (with recovery between 95.5% and 100.8%). The method has been demonstrated as a powerful tool for the functional ingredients analysis and quality control of rosemary and its extracts in a cost- and time-effective manner.

scholarly journals Quick extraction and direct determination of amino acids from plants by hydrophilic interaction liquid chromatography (HILIC) and high-performance liquid chromatography-mass spectrometry without derivatization

2021 ◽  
Vol 252 ◽  
pp. 02055
Author(s):  
Xuemei Chen ◽  
Dejian Feng ◽  
Yan Zou ◽  
Huaiping Li ◽  
Hang Song
Keyword(s):  
Amino Acids ◽  
Liquid Chromatography ◽  
Analytical Method ◽  
High Performance ◽  
Water Solution ◽  
Human Life ◽  
Multiple Reaction Monitoring ◽  
Direct Determination ◽  
High Sensitivity

Amino acids are naturally compound in many plants and have a essential effects on human life. This work presents a simple and rapid analytical method for direct determination of amino acids without derivatization. The preparation method of samples was green and quick, which extracted amino acids with water in 10 min, and separated on a HILIC-Z (2.1 mm×100 mm, 2.7 μm i.d.) using acetonitrile-water solution as mobile phase, and then detected under ESI-multiple reaction monitoring mode. Satisfactory determination of 21 underivatized amino acids from three different plants was achieved in 15 min. This method showed a good linearity (R2 > 0.99) for the analyst and the detection limits (LOD) were 0.53 mg/kg–10.39 mg/kg for the amino acids. The average recoveries were in the range of 80%–120% at spiked concentrations. The analytical method is high sensitivity, accuracy and analytical efficiency, meanwhile it may be used for the analysis of amino acids in other plants.

Developing a High-performance Liquid Chromatography Method for Simultaneous Determination of Loratadine and its Metabolite Desloratadine in Human Plasma

2020 ◽  
Vol 20 (13) ◽  
pp. 1053-1059
Author(s):  
Mahmoud M. Sebaiy ◽  
Noha I. Ziedan
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Human Plasma ◽  
High Performance ◽  
Allergic Diseases ◽  
Reversed Phase ◽  
Hplc Method ◽  
H1 Receptor ◽  
Chromatography Method

Background: Allergic diseases are considered as the major burden on public health with increased prevalence globally. Histamine H1-receptor antagonists are the foremost commonly used drugs in the treatment of allergic disorders. The target drug in this study, loratadine, belongs to this class of drugs and its biometabolite desloratadine which is also a non-sedating H1 receptor antagonist with anti-histaminic activity being 2.5 to 4 times greater than loratadine. This study aimed to develop and validate a novel isocratic Reversed-phase High-Performance Liquid Chromatography (RP-HPLC) method for rapid and simultaneous separation and determination of loratadine and its metabolite, desloratadine in human plasma. Methods: The drug extraction method from plasma was based on protein precipitation technique. The separation was carried out on a Thermo Scientific BDS Hypersil C18 column (5μm, 250 x 4.60 mm) in a mobile phase of MeOH: 0.025M KH2PO4 adjusted to pH 3.50 using orthophosphoric acid (85: 15, v/v) at an ambient temperature. The flow rate was maintained at 1 mL/min and maximum absorption was measured using the PDA detector at 248 nm. Results: The retention times of loratadine and desloratadine in plasma samples were recorded to be 4.10 and 5.08 minutes, respectively, indicating a short analysis time. Limits of detection were found to be 1.80 and 1.97 ng/mL for loratadine and desloratadine, respectively, showing a high degree of sensitivity of the method. The method was then validated according to FDA guidelines for the determination of the two analytes in human plasma. Conclusion: The results obtained indicate that the proposed method is rapid, sensitive in the nanogram range, accurate, selective, robust and reproducible compared to other reported methods.

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