scholarly journals Deproteinization as a Rapid Method of Saliva Purification for the Determination of Carbamazepine and Carbamazepine-10,11 Epoxide

2020 ◽  
Vol 9 (4) ◽  
pp. 915 ◽  
Author(s):  
Ewelina Dziurkowska ◽  
Marek Wesolowski
Keyword(s):  
Acid Solution ◽  
Formic Acid ◽  
Rapid Method ◽  
Mobile Phase ◽  
Solid Phase ◽  
Formic Acid Solution ◽  
Extraction Procedures ◽  
Sample Purification

Saliva is a valuable diagnostic material that, in some cases, may replace blood. However, because of its different composition, its use requires the development of new, or the modification of existing, extraction procedures. Therefore, the aim of the study was to develop a method of saliva purification that would enable the determination of carbamazepine and its metabolite, carbamazepine-10,11 epoxide. When comparing two methods of sample purification (Solid Phase Extration (SPE) and deproteinization), it was found that the second method yielded more favorable results. A 1% formic acid solution in acetonitrile was used for extraction. The samples were shaken and centrifuged, and the supernatant obtained was evaporated and dissolved in a mobile phase, then chromatographically analyzed. The developed method was validated by determining its linearity in the range of 10–5000 ng/mL for both analytes. Intra- and inter-day precision did not exceed 14%. In order to check the usefulness of the method, both analytes were determined in the saliva samples from 20 patients treated with carbamazepine. The content of both analytes was detected and determined in all of the tested samples of saliva. It was found that the method developed is rapid, sensitive, reliable, and can be used to monitor the concentration of carbamazepine and metabolite in patients’ saliva.

scholarly journals Rapid Determination of Fumagillin Residues in Honey by Liquid Chromatography–Tandem Mass Spectrometry Using the QuEChERS Method

2011 ◽  
Vol 94 (3) ◽  
pp. 878-885 ◽  
Author(s):  
Maki Kanda ◽  
Takeo Sasamoto ◽  
Kazue Takeba ◽  
Hiroshi Hayashi ◽  
Tomoko Kusano ◽  
...  
Keyword(s):  
Formic Acid ◽  
Solid Phase ◽  
Rapid Determination ◽  
Quechers Method ◽  
Formic Acid Solution ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Sample Preparation Procedure ◽  
Gradient Mode

Abstract A new, rapid, and efficient method for determining the fumagillin residues in honey was developed. The samples extracted were analyzed using LC/MS/MS. Chromatographic separation of fumagillin was performed in gradient mode on a C8 column (100 × 2.0 mm, 5 μm) at 40°C. The mobile phase consisted of a mixture of 2 mM ammonium formate–0.01% formic acid solution and methanol; the flow rate was set to 0.2 mL/min. Under these conditions, it was possible to measure fumagillin and its isomers as a single peak. The sample preparation procedure used is based on the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, which is fast (approximately 30 min) and uses less organic solvent. The fumagillin was extracted with acetonitrile containing 0.1% formic acid, then purified using a solid-phase extraction method with an Oasis® mixed-mode weak anion-exchange cartridge. The overall recovery of fumagillin ranged from 88.1 to 99.4%; the intra- and interassay CVs were <4.5% and <4.9%, respectively. The LOQ was 0.1 μg/kg. LC/MS/MS coupled with the QuEChERS method showed strong potential as a method for determining fumagillin residues in honey.

scholarly journals Simultaneous Determination of Malachite Green, Chloramphenicols, Sulfonamides, and Fluoroquinolones Residues in Fish by Liquid Chromatography-Mass Spectrometry

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yongping Chen ◽  
Sudong Xia ◽  
Xianqin Han ◽  
Zhiru Fu
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Formic Acid ◽  
Simultaneous Determination ◽  
Mobile Phase ◽  
Solid Phase ◽  
Hydrophilic Lipophilic Balance ◽  
Relative Standard ◽  
Fish Samples

A fast-analytical method using simplified extraction has been developed for the simultaneous determination of 42 compounds from 4 different classes of veterinary drugs (amphenicols, triphenylmethane, fluoroquinolones, and sulfonamides) in fish by reverse phase liquid chromatography-tandem mass spectrometry. The selection of extraction reagents was optimized using different types of microfiltration membrane, mobile phase, and LC column. Samples were extracted using 0.4% hydrochloric acid in acetonitrile and ethyl acetate and then were cleaned up using solid-phase extraction Cleanert Alumina N columns (500 mg) and Oasis hydrophilic-lipophilic balance (HLB) cartridges. The chromatographic separation was performed on a XR-ODS C8 column using a mobile phase of (A) 0.1% formic acid and 2 mM ammonium acetate and (B) 0.1% formic acid acetonitrile at a flow rate of 0.25 mL·min−1. The results indicated 67.7–112.8% recovery of 42 compounds with an intra- and interday relative standard deviations less than 10%. The limits of quantification for analytes were in the range of 0.3–1.0 μg kg−1 for samples which were satisfactory to support future surveillance monitoring. The method applicability was checked by analyzing 30 fish samples collected from local markets. Two fish samples surpassed the established MRL of 100 μg kg−1 with values of 104 μg kg−1 and 112 μg kg−1.

scholarly journals Quantitative Determination of Azithromycin in Human Plasma by Liquid Chromatography–Mass Spectrometry and its Application in Pharmackokinetic Study

2012 ◽  
Vol 11 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Maizbha Uddin Ahmed ◽  
Mohammad Safiqul Islam ◽  
Tasmin Ara Sultana ◽  
AGM Mostofa ◽  
Muhammad Shahdaat Bin Sayeed ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Solid Phase ◽  
Internal Standard ◽  
Extraction Process ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Linear Concentration Range ◽  
Linear Concentration

Azithromycin is an effective and well-known antimicrobial agent. In the present study, a simple, sensitive and specific LC/MS/MS method has been developed and validated for the quantification of Azithromycin in  human serum samples using Clarithromycin as internal standard. Azithromycin was extracted from biological matrix  by using solid phase extraction process. The chromatographic separation was performed on Luna C18 (3 ?, 2x150   mm) column with a mobile phase consisting of 35 mM ammonium acetate buffer (mobile phase-A) and acetonitrile  and methanol in ratio of 90:10 ( as mobile phase-B) at a flow rate of 0.25 mL/min. The method was validated over a  linear concentration range of 0.5?50.0 ng/mL and limit of quantification (LOQ) was 0.5 ng/mL with a coefficient of  correlation (r2) = 0.9998. The intra-day and inter-day precision expressed as relative standard deviation were 1.64% – 8.43% and 2.32% – 9.92%, respectively. The average recovery of azithromycin from serum was 98.11%. The method  was successfully applied to a pharmacokinetic study after oral administration of Azithromycin 200 mg/5 ml suspension in healthy Bangladeshi volunteers. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12488 Dhaka Univ. J. Pharm. Sci. 11(1): 55-63, 2012 (June)

Hydrogen?Oxygen Flame as a Radical Source for Aqueous-Phase Reaction: Carboxylation of Propylamine in Aqueous Formic Acid Solution

ChemInform ◽  
2005 ◽  
Vol 36 (15) ◽  
Author(s):  
Shinya Nomoto ◽  
Daisuke Yoshimura ◽  
Masayosi Hagiwara ◽  
Masaki Kozono ◽  
Masanori Terasaki ◽  
...  
Keyword(s):  
Acid Solution ◽  
Formic Acid ◽  
Aqueous Phase ◽  
Phase Reaction ◽  
Formic Acid Solution ◽  
Oxygen Flame ◽  
Aqueous Formic Acid

scholarly journals HPLC determination of hydrochlorothiazide in urine after solid-phase extraction

2005 ◽  
Vol 51 ◽  
pp. 23-28 ◽  
Author(s):  
Violeta Ivanova ◽  
Dragica Zendelovska ◽  
Marina Stefova
Keyword(s):  
Particle Size ◽  
Solid Phase Extraction ◽  
Mobile Phase ◽  
Solid Phase ◽  
Hplc Method ◽  
Phase Extraction ◽  
Hplc Separation ◽  
Isocratic Elution ◽  
Extraction Recovery

A simple, rapid and precise HPLC method has been developed for the assay of hydrochlorothiazide in urine. The clean-up of the urine samples was carried out by solid-phase extraction using HLB cartridges. Extraction recovery was 94.00-100.28 %. HPLC separation was performed with isocratic elution on Hypersil BDS C18 column (100 x 4.0 mm I.D., 3 µm particle size) protected with appropriate guard column. The mobile phase was 18 % acetonitrile and 0.025 mol/L solution of KH2PO4, pH 4 at flow rate of 0.3 mL/min. Detection of the substances was performed at 220 nm. The calibration curves were linear in the range of 2-50 µg/mL. The developed method is validated by checking its accuracy, precision and stability. The detection limit is 2 µg/mL hydrochlorothiazide. The method is proved to be convenient for routine analysis of hydrochlorothiazide in urine.

scholarly journals Determination of Nitroimidazole Residues in Porcine Urine by Liquid Chromatography/TandemMass Spectrometry

2006 ◽  
Vol 89 (4) ◽  
pp. 1116-1119 ◽  
Author(s):  
Xi Xia ◽  
Xiaowei Li ◽  
Jianzhong Shen ◽  
Suxia Zhang ◽  
Shuangyang Ding ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Solid Phase ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Mass Spectrometry System ◽  
Ionization Mode ◽  
Positive Ion ◽  
Mode A

Abstract A reliable and sensitive method was developed for determination of nitroimidazoles in porcine urine. Sample preparation involves an extraction with ethyl acetate, followed by a solid-phase extraction cleanup step. The final extract is injected into the liquid chromatography/tandem mass spectrometry system in the positive-ion electrospray ionization mode. A C8 column with water and acetonitrile as the mobile phase is used for chromatographic separation under gradient conditions. Overall average recoveries ranged from 83 to 107%. The limits of detection ranged from 0.03 to 0.05 ng/mL, and the limits of quantitation, from 0.1 to 0.2 ng/mL.

Determination of Ardacin in Various Silage Feed Diets by a Rapid Liquid Chromatographic Assay

1995 ◽  
Vol 78 (1) ◽  
pp. 16-21
Author(s):  
Sylvia V B Fagan ◽  
Connie Gombatz ◽  
Hafez Abdel-Kader ◽  
Govind Menon
Keyword(s):  
Mobile Phase ◽  
Solid Phase ◽  
Chromatographic System ◽  
Method Of Calculation ◽  
Feed Formulation ◽  
Sample Extract ◽  
Liquid Chromatographic ◽  
Solid Phase Extract ◽  
Cyano Column

Abstract A method is presented for the detection and quantitation of Ardacin in silage feed diets by liquid chromatography, using a cyano column and an acetonitrile–methanol water mobile phase modified with trifluoroacetic acid. This method includes comprehensive procedures for extracting Ardacin from various silage feed formulations, cleaning up the extracted sample by using solid-phase extractions, and analyzing the eluted solid-phase extract with a suitable liquid chromatographic system. Ardacin was extracted from the silage feed formulations with 50% acetonitrile and 50% 0.1 M KOH. The extract was cleaned up with a wide-pore butyl solidphase extraction cartridge. The sample extract was chromatographed and quantified at 220 nm, using an external method of calculation. Recoveries of the medicated silage feed formulation ranged from 72.1 ± 1.7% to 109.1 ± 2.4%, depending on the sites and types of formulation analyzed.

scholarly journals Liquid chromatography – tandem mass spectrometry method for the determination of ten tetracycline residues in muscle samples

2015 ◽  
Vol 59 (3) ◽  
pp. 345-352 ◽  
Author(s):  
Anna Gajda ◽  
Andrzej Posyniak
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Formic Acid ◽  
Solid Phase ◽  
Acid Extraction ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Abstract A liquid chromatography – tandem mass spectrometry (LC-MS/MS) method for the determination of oxytetracycline (OTC), 4-epi oxytetracycline (4-epi OTC), tetracycline (TC), 4-epi tetracycline (4-epi TC), chlortetracycline (CTC), 4-epi chlortetracycline (4-epi CTC), doxycycline (DC), minocycline (MINO), methacycline (META) and rolitetracycline (ROLI) residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X) reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

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