scholarly journals A Reliable Semiautomated Method for the Determination of Total Thiamine in Whole Blood by the Thiochrome Method with High-Performance Liquid Chromatography

Author(s):  
Jaap Schrijver ◽  
Andries J Speek ◽  
Jan A Klosse ◽  
Herman J M Van Rijn ◽  
Wil H P Schreurs

A sensitive and reliable method for the determination of total thiamine (vitamin B1) in whole blood has been developed which is suited for routine analysis. After extraction, and enzymatic hydrolysis of thiamine phosphate esters, thiamine is separated from interfering compounds by a fully automated high-performance liquid chromatographic (HPLC) system. Thiamine is detected fluorometrically as thiochrome. By calculating the concentration of thiamine on-line with the aid of a computer, it is possible to complete one analysis within four hours. Routine thiamine determinations can be carried out in a series of 120 samples within 48 hours. The within-assay and between-assay coefficients of variation of the analysis of total thiamine in whole blood were 4·2 and 4·4%, respectively. The between-assay analytical recovery of thiamine diphosphate added to blood samples was 99·9 ± 11·7% (mean ± SD). The HPLC method described has been applied also to the analysis of thiamine in plasma and erythrocytes. In agreement with other reports, it was found that about 80% of total thiamine of whole blood is present in the erythrocytes. Reference values of thiamine in whole blood of the human were found in the range 95–155 nmol/l.

1988 ◽  
Vol 34 (12) ◽  
pp. 2502-2503 ◽  
Author(s):  
P A Hynning ◽  
P Anderson ◽  
U Bondesson ◽  
L O Boréus

Abstract A high-performance liquid chromatographic (HPLC) method for determining verapamil and norverapamil in plasma is presented and compared with gas chromatography/mass spectrometry (GC-MS). The plasma samples were extracted at alkaline pH with hexane containing 2-butanol (20 mL/L) and then back-extracted into phosphate buffer (0.1 mol/L, pH 3.0). For chromatography we used a reversed-phase column (Supelcosil LC-18 DB) with a mobile phase of the phosphate buffer and acetonitrile (70/30 by vol). Fluorescence detection was used (excitation at 203 nm, emission at 320 nm). Overall analytical recovery was 85%. Standard curves were linear from 1 to 1000 micrograms/L. The detection limit was 1 microgram/L. The assays are accurate and precise. We found no interferences by those substances tested. Results by HPLC and GC-MS agreed well (r = 0.99) for both verapamil and norverapamil determinations.


1982 ◽  
Vol 65 (3) ◽  
pp. 580-583
Author(s):  
James W Miles ◽  
Dwight L Mount

Abstract An HPLC method for the determination of temephos in temephos technical and formulated products has been subjected to an international collaborative study with 14 laboratories participating. Samples were extracted with ethyl acetate and eluted on a silica gel column with ethyl acetate-hexane (1 + 9); p-nitrophenyl p-nitrobenzoate served as the internal standard. Collaborators were furnished samples of technical, 20 and 50% emulsifiable concentrates, 50% water-dispersible powder, and 1% sand granules. The coefficients of variation of the values obtained on the 5 samples were 1.21,2.02,1.26,1.89, and 9.90%, respectively. The method has been adopted official first action.


2015 ◽  
Vol 39 (3) ◽  
Author(s):  
Werner J. Heinz ◽  
Dieter Kuschak ◽  
Diana Schirmer ◽  
Anna Grau ◽  
Daniela Keller ◽  
...  

AbstractTelaprevir (TVR) was approved by the FDA in May 2011 for the treatment of hepatitis C. This protease inhibitor converts into two diastereomers with significant difference in antiviral activity. Clinical efficacy has been correlated with serum concentrations. Therefore, a sensitive and selective high-performance liquid chromatographic method for the simultaneous determination of both clinically relevant diastereomers of TVR was developed. Linearity ranged from 20 to 10,000 ng/mL. The coefficients of variation were <7.3%, and accuracy was between −4.0 and 5.4%. In 105 clinical samples, both diastereomers of TVR had a high degree of correlation to each other, but concentrations showed a broad range and an increase during therapy.


2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Suying Ma ◽  
Haixia Lv ◽  
Xiaojun Shang

A high performance liquid chromatographic (HPLC) method with UV detector for the determination of dyclonine hydrochloride and a gas chromatography (GC) method with flame ionization detector (FID) for the determination of camphor and menthol in lotion were developed. The developed HPLC method involved using a SinoChoom ODS-BP C18reversed-phase column (5 μm, 4.6 mm × 200 mm) and mobile phase consisting of acetonitrile : water : triethylamine in a ratio of 45 : 55 : 1.0; pH was adjusted to 3.5 with glacial acetic acid. The developed GC method for determination of camphor and menthol involved using an Agilent 19091J-413 capillary chromatographic column (30 m × 320 μm × 0.25 μm). The two methods were validated according to official compendia guidelines. The calibration of dyclonine hydrochloride for HPLC method was linear over the range of 20–200 μg/mL. The retention time was found at 6.0 min for dyclonine hydrochloride. The calibration of camphor and menthol of GC method was linear over the range of 10–2000 μg/mL. The retention time was found at 2.9 min for camphor and 3.05 min for menthol. The proposed HPLC and GC methods were proved to be suitable for the determination of dyclonine hydrochloride, camphor, and menthol in lotion.


INDIAN DRUGS ◽  
2018 ◽  
Vol 55 (06) ◽  
pp. 63-68
Author(s):  
R. Raut ◽  
◽  
A. Patil ◽  
V. K Munipalli ◽  
M. Patel ◽  
...  

A simple precise and rapid Reverse Phase High Performance Liquid Chromatographic (RP-HPLC) method has been developed for quantitative determination of Regorafenib in tablet dosage form. In this method Hypersil Gold (C18, 150mm× 4.6mm id, 3μ) column with mobile phase consisting of Trifluoroacetic acid (0.2% v/v) and Acetonitrile in the ratio of (50: 50 v/v) at 400C in an isocratic mode was used. The detection was carried out at 260 nm and 20μL injection volume was selected with the flow rate 1mL/min. The linearity range of Regorafenib shows concentration between 5-200 μg/mL. The regression coefficient obtained was 0.999. Retention time of Regorafenib was found to be 6.49 minutes. Acetonitrile and Water in the ratio of (3:1) was used as a diluent. The method was validated as per ICH guidelines and is simple, fast, accurate, precise and can be applied for routine quality control analysis of Regorafenib in tablet dosage form.


INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (07) ◽  
pp. 43-49
Author(s):  
B.P. Manjula ◽  
V. G Joshi ◽  
Siddamsetty Ramachandra Setty ◽  
M Geetha ◽  

Tea tree oil, an active ingredient of skin, hair and nail care cosmeceuticals, has claims for topical antimicrobial, analgesic and anti-inflammatory activity. Its complex composition is governed by ISO 4730:2017. Terpinene-4-ol is the principal constituent of the oil (35% - 48%) followed by γ-terpinene (14% -28%), α-terpinene (6%-12%) and 1,8-cineole (≤15%). A reversed-phase, isocratic high performance liquid chromatographic method has been developed and validated for routine determination of tea tree oil based on1,8-cineole content in bulk and commercially available cosmeceuticals using C18 column, methanol-water (70:30 v/v) as mobile phase and flow rate of 1mL/min. UV detection was done at 200 nm. Linearity of the method was established for 20-100μL/mL (R2 = 0.9992) with LOD, LOQ values of 0.5594 μL/mL and 5.5941μL/mL respectively. The % RSD values for robustness and precision were <1% and recovery ranged between 99.09-102.96%. The method was successfully applied for determination of 1,8-cineole content in cosmeceuticals.


1988 ◽  
Vol 34 (1) ◽  
pp. 87-90 ◽  
Author(s):  
K Abe ◽  
R Konaka

Abstract We describe a "high-performance" liquid-chromatographic method for determining 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) in human urine. MHPG is separated on a reversed-phase column with isocratic elution, oxidized with sodium metaperiodate, and its absorbance measured at 365 nm. This method shows higher specificity, less interference for MHPG than methods involving electrochemical or fluorescence detection. Post-column derivatization of MHPG with periodate yields vanillin. The detection limit (twice the signal-to-noise ratio) in urine samples was 0.08 mg/L. Mean analytical recovery was 72%. Within-assay and day-to-day CVs were 2.9% and 6.5%, respectively. Reference intervals for MHPG in 24-h urine from apparently healthy subjects were 0.85-3.24 mg/day for men and 0.63-2.20 mg/day for women. In terms of creatinine excretion, the respective reference intervals were 0.55-1.99 and 0.70-1.96 mg per gram of creatinine.


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