Quantification of tea‐derived catechins without the requirement for respective calibration curves by single reference liquid chromatography based on relative molar sensitivity

2020 ◽  
Author(s):  
Miki Takahashi ◽  
Yuzo Nishizaki ◽  
Naoko Masumoto ◽  
Naoki Sugimoto ◽  
Kyoko Sato ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Calibration Curves ◽  
Reference Liquid

scholarly journals High-performance liquid chromatography and derivative spectrophotometry for simultaneous determination of pravastatin and fenofibrate in the dosage form

2014 ◽  
Vol 64 (4) ◽  
pp. 433-446 ◽  
Author(s):  
Mohamed M. Hefnawy ◽  
Mostafa S. Mohamed ◽  
Mohammed A. Abounassif ◽  
Amer M. Alanazi ◽  
Gamal A. E. Mostafa
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
High Performance ◽  
Particle Diameter ◽  
Second Order ◽  
Derivative Spectrophotometry ◽  
Order Derivative ◽  
Calibration Curves

Abstract High performance liquid chromatography (HPLC) and second-order derivative spectrophotometry have been used for simultaneous determination of pravastatin (PS) and fenofibrate (FF) in pharmaceutical formulations. HPLC separation was performed on a phenyl HYPERSIL C18 column (125 mm × 4.6 mm i.d., 5 μm particle diameter) in the isocratic mode using a mobile phase acetonitrile/0.1 % diethyl amine (50:50, V/V, pH 4.5) pumped at a flow rate of 1.0 mL min-1. Measurement was made at 240 nm. Both drugs were well resolved on the stationary phase, with retention times of 2.15 and 5.79 min for PS and FF, respectively. Calibration curves were linear (R = 0.999 for PS and 0.996 for FF) in the concentration range of 5-50 and 20-200 µg mL-1 for PS and FF, respectively. Pravastatin and fenofibrate were quantitated in combined preparations also using the second-order derivative response at 237.6 and 295.1 nm for PS and FF, respectively. Calibration curves were linear, with the correlation coefficient R = 0.999 for pravastatin and fenofibrate, in the concentration range of 5-20 and 3-20 µg mL-1 for PS and FF, respectively. Both methods were fully validated and compared, the results confirmed that they were highly suitable for their intended purpose.

scholarly journals Toxicological analysis of satratoxins, the main toxins in the mushroom Trichoderma cornu-damae, in human serum and mushroom samples by liquid chromatography–tandem mass spectrometry

2020 ◽  
Author(s):  
Hikoto Ohta ◽  
Daisuke Watanabe ◽  
Chie Nomura ◽  
Daichi Saito ◽  
Koichi Inoue ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Human Serum ◽  
Tandem Mass ◽  
Toxicological Analysis ◽  
Chromatography Tandem Mass Spectrometry ◽  
Calibration Curves ◽  
Liquid Chromatography Tandem Mass ◽  
Analytical Standards

Abstract Purpose Many poisoning cases involving the deadly toxic mushroom Trichoderma cornu-damae have been reported, but there are very few reports on toxicological analysis of the poisoning. In this study, a simple and sensitive method was developed for detecting and quantifying satratoxins, which are the main toxins found in T. cornu-damae, in human serum and mushroom samples. Methods The four main toxins, namely, satratoxin H and its 12′-acetate, 13′-acetate and 12′,13′-diacetate, were isolated from T. cornu-damae and used as analytical standards. These standards were spiked into human serum and effective methods were developed for extraction and detection/quantification using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Quantification of satratoxins in T. cornu-damae samples was performed by the standard addition method. Results Although satratoxins, which have neutral terpene structures, showed very low sensitivities in conventional LC–MS/MS analysis, they could be detected with enough sensitivity by our developed method. In human serum, the limit of detection was 0.1 ng/mL and the limit of quantification was 1 ng/mL for all four satratoxins. The recovery rate ranged from 70.5 to 86.6%, and the coefficients of determination for calibration curves were > 0.999. Satratoxins in T. cornu-damae samples were also well detected and quantified with coefficients of determination for calibration curves of > 0.997 and intraday/interday precision (relative standard deviation) ranging from 2.98 to 10.3%. Conclusions To our knowledge, this is the first report of toxicological analysis of satratoxins using analytical standards.

scholarly journals Determination of Nebivolol Hydrochloride and Hydrochlorothiazide in Tablets by First-Order Derivative Spectrophotometry and Liquid Chromatography

2008 ◽  
Vol 91 (5) ◽  
pp. 1075-1082 ◽  
Author(s):  
Dimal A Shah ◽  
Kashyap K Bhatt ◽  
Rajendra S Mehta ◽  
Sunil L Baldania
Keyword(s):  
Liquid Chromatography ◽  
Internal Standard ◽  
Reversed Phase ◽  
Dosage Forms ◽  
Derivative Spectrophotometry ◽  
Order Derivative ◽  
First Order ◽  
Calibration Curves ◽  
Phase Liquid ◽  
Nebivolol Hydrochloride

Abstract Two simple and accurate methods for analysis of nebivolol hydrochloride (NEB) and hydrochlorothiazide (HCTZ) in their combined dosage forms were developed using first-order derivative spectrophotometry and reversed-phase liquid chromatography (LC). NEB and HCTZ in their combined dosage forms (tablets) were quantified using first-derivative responses at 294.6 and 334.6 nm in the spectra of their solutions in methanol. The calibration curves were linear in the concentration range of 840 g/mL for NEB and 1060 g/mL for HCTZ. LC analysis was performed on a Phenomenex Gemini C18 column (250 4.6 mm id, 5 m particle size) in the isocratic mode with 0.05 M potassium dihydrogen phosphateacetonitrilemethanol (30 + 20 + 50, v/v/v; pH 4) mobile phase at a flow rate of 1 mL/min. Detection was made at 220 nm. Both of the drugs and the internal standard (ezetimibe) were well resolved with retention times of 5.1 min for NEB, 2.9 min for HCTZ, and 8.2 min for ezetimibe. The calibration curves were linear in the concentration range of 114 g/mL for NEB and 0.328 g/mL for HCTZ. Both methods were validated and found to be accurate, precise, and specific, and results were compared statistically. Developed methods were successfully applied for the estimation of NEB and HCTZ in their combined dosage forms.

scholarly journals Simultaneous determination of steviol glycosides in stevia by high performance liquid chromatography

2019 ◽  
Vol 2 (4) ◽  
pp. 2-8
Author(s):  
Huyen Trang Luu Thi ◽  
Thanh Huong Doan Thi ◽  
Trang Vu Thi ◽  
Son Tran Cao ◽  
Anh Huong Nguyen Thi ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
High Performance ◽  
Stevia Rebaudiana ◽  
Steviol Glycosides ◽  
Rebaudioside A ◽  
Calibration Curves ◽  
Oasis Hlb

A method for determination of steviol glucosides in stevia using high performance liquid chromatography was developed and validated. The compounds were extracted from the matrices with methanol for 60 minutes, cleaned by Oasis HLB column and then determined by HPLC using C18 column (250 mm x 4.6 mm x 5 µm) and PDA detector. The calibration curves were linear in range of 1 to 100 μg/mL; the RSD was of 1.39 ­ 2.85%; and the recovery was of 93 ­ 105%. The method was applied to analyze 09 stevia samples collected from markets in Hanoi (including dry stevia rebaudiana, stevia powder). The results showed that composition of steviol glycosides differs from sample to sample. Besides, stevioside and rebaudioside A are the most abundant steviol glycosides in the samples.

scholarly journals Study on the Synthesis of Methylated Reference and Their Application in the Quantity of Curcuminoids Using Single Reference Liquid Chromatography Based on Relative Molar Sensitivity

2022 ◽  
Vol 70 (1) ◽  
pp. 25-31
Author(s):  
Miki Takahashi ◽  
Koji Morimoto ◽  
Yuzo Nishizaki ◽  
Naoko Masumoto ◽  
Naoki Sugimoto ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Reference Liquid

Liquid Chromatographic Determination Of Three Sulfonamides In Animal Tissue And Egg

1990 ◽  
Vol 73 (6) ◽  
pp. 990-992 ◽  
Author(s):  
Shozo Horii ◽  
Chie Momma ◽  
Kayoko Miyahara ◽  
Tsutomu Maruyama ◽  
Masao Matsumoto
Keyword(s):  
Liquid Chromatography ◽  
Detection Limits ◽  
Chromatographic Determination ◽  
Animal Production ◽  
Animal Tissue ◽  
Feed Additive ◽  
Calibration Curves ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Sulfonamides are widely used as a feed additive in animal production In Japan. The present paper is a determination of 3 sulfonamides: sulfamethazine (SMZ), sulfamonomethoxlne [SMX, 4-amino-/V-(3-methoxypyrazlnyl)-benzenesulfonamlde], and suifadimethoxine (SDX) in animal tissue and egg by liquid chromatography (LC). Tissues were extracted with acetonltrlle and fat was removed by liquid/liquid partition. The sulfonamides were purified by an ODS cartridge column; then each compound was separated by an ODS LC column and detected at 268 nm. Quantification levels were 0.02 ppm for SMZ and SMX, and 0.04 ppm for SDX; detection limits were 0.01 ppm for SMZ and SMX, and 0.02 ppm for SDX. Calibration curves were linear between 2 and 40 ng for SMZ and SMX, and between 4 and 80 ng for SDX. Recoveries from muscle and egg samples spiked with 1-2 /μg/10 g were 8 1 - 98%.

scholarly journals Estimation of Atorvastatin Calcium and Fenofibrate in Tablets by Derivative Spectrophotometry and Liquid Chromatography

2007 ◽  
Vol 90 (3) ◽  
pp. 700-705 ◽  
Author(s):  
Naresh V Nakarani ◽  
Kashyap K Bhatt ◽  
Rutva D Patel ◽  
Hemaxi S Bhatt
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Derivative Spectrophotometry ◽  
Second Derivative ◽  
Atorvastatin Calcium ◽  
Calibration Curves ◽  
Phase Liquid ◽  
Tablet Formulations ◽  
Method Analysis ◽  
Isocratic Mode

Abstract Two simple and accurate methods to determine atorvastatin calcium (ATO) and fenofibrate (FEN) in combined dosage forms were developed using second-derivative spectrophotometry and reversed-phase liquid chromatography (LC). ATO and FEN in combined preparations (tablets) were quantitated using the second-derivative responses at 245.64 nm for ATO and 289.56 nm for FEN in spectra of their solution in methanol. The calibration curves were linear [correlation coefficient (r) = 0.9992 for ATO and 0.9995 for FEN] in the concentration range of 315 g/mL for ATO and FEN. In the LC method, analysis was performed on a Hypersil ODS-C18 column (250 mm 4.6 mm id, 5 m particle size) in the isocratic mode using the mobile phase methanol-water (90 + 10, v/v), adjusted to pH 5.5 with orthophosphoric acid, at a flow rate of 1 mL/min. Measurement was made at a wavelength of 246.72 nm. Both drugs were well resolved on the stationary phase, and the retention times were 1.95 min for ATO and 5.50 min for FEN. The calibration curves were linear (r = 0.9985 for ATO and 0.9976 for FEN) in the concentration range of 315 g/mL for ATO and FEN. Both methods were validated, and the results were compared statistically. They were found to be accurate, precise, and specific. The methods were successfully applied to the estimation of ATO and FEN in combined tablet formulations.

Adsorption of Aqueous Nonylphenol Ethoxylate Surfactants on Metal Sample Loops: Effect on Quantitation by Liquid Chromatography

1990 ◽  
Vol 73 (2) ◽  
pp. 322-324
Author(s):  
B B Sithole ◽  
B Zvilichovsky ◽  
C Lapointe ◽  
L H Allen
Keyword(s):  
Stainless Steel ◽  
Liquid Chromatography ◽  
Aqueous Solutions ◽  
Metal Surfaces ◽  
Peak Height ◽  
Surfactant Adsorption ◽  
Good Precision ◽  
Metal Sample ◽  
Nonylphenol Ethoxylate ◽  
Calibration Curves

Abstract In aqueous solutions of Igepal CO 610, a nonionic nonylphenol ethoxylate surfactant, adsorption of the surfactant takes place onto stainless steel metal surfaces. This adsorption results in increased peak height of the surfactant when a sample loop is purged with increasing volumes of the surfactant. This, in turn, affects the quantitation of the surfactant. However, the adsorption is reproducible at constant purging volumes and results in calibration curves with good precision.

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