Determination of thiamin and thiamin phosphate esters in blood by liquid chromatography with post-column derivatization.

1983 ◽  
Vol 29 (12) ◽  
pp. 2073-2075 ◽  
Author(s):  
M Kimura ◽  
Y Itokawa
Keyword(s):  
High Performance ◽  
Sodium Hydroxide Solution ◽  
Potassium Ferricyanide ◽  
Phosphate Esters ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Thiamin Pyrophosphate

Abstract We demonstrate a liquid-chromatographic method involving post-column derivatization for determining the concentration of thiamin and its phosphate esters in human blood. Blood, erythrocytes, or plasma is deproteinized and centrifuged. Aliquots of the samples are applied to a mu Bondapak C18 column attached to a "high-performance" liquid chromatograph. Addition of potassium ferricyanide/sodium hydroxide solution to the column effluent with a proportioning pump converts thiamin phosphates into fluorophores, the intensities of which are measured with a spectrofluorophotometer. Thiamin, thiamin monophosphate, thiamin pyrophosphate, and thiamin triphosphate eluted as single peaks; no coeluting substances were detected. Thiamin pyrophosphate was the ester present in greatest concentration, followed by thiamin triphosphate; thiamin monophosphate and thiamin were present in slight amounts. This method allows easy determination of thiamin and its phosphate esters in 0.1 mL of blood.

Liquid-chromatographic determination of the total thiamin content of blood.

1982 ◽  
Vol 28 (1) ◽  
pp. 29-31 ◽  
Author(s):  
M Kimura ◽  
T Fujita ◽  
Y Itokawa
Keyword(s):  
High Performance ◽  
Chromatographic Determination ◽  
Potassium Ferricyanide ◽  
Phosphate Esters ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid-chromatographic method for determining the total thiamin content of blood is presented. Blood is deproteinized and incubated with Aspergillus oryzae carboxyl proteinase (EC 3.4.23.6; Takadiastase) to convert thiamin phosphate esters to free thiamin. An aliquot of the sample is applied to the column (Shodex OH-Pak M-414) of a high-performance liquid chromatograph. A 100 mg/L solution of potassium ferricyanide in 150 g/L sodium hydroxide is added to the column effluent with a proportioning pump, to convert thiamin into a fluorophore. The intensity of the fluorophore is measured with a spectrofluorophotometer and recorded graphically. The total thiamin in each blood sample appears as a single peak, and no co-eluting substance was detected. This method is simple, highly reproducible, and rapid, and its sensitivity is sufficient for determination of the thiamin content of 0.1-mL blood samples.

Determination of Coumaphos and Its Oxygen Analog in Eggs and Milk by Using a Multiresidue Method with Liquid Chromatographic Quantitation and Capillary Gas Chromatographic/Mass Spectrometric Confirmation

1983 ◽  
Vol 66 (6) ◽  
pp. 1353-1357
Author(s):  
Richard T Krause ◽  
Zhao Min ◽  
Sharona H Shotkin
Keyword(s):  
High Performance ◽  
Mass Spectrometric ◽  
Fluorescence Detector ◽  
High Performance Liquid Chromatograph ◽  
Liquid Chromatograph ◽  
Multiresidue Method ◽  
Oxygen Analog ◽  
Liquid Chromatographic ◽  
Chromatographic Mass

Abstract A multiresidue method for carbamate insecticides was adapted for the determination of coumaphos and its oxygen analog in eggs and milk. Eggs were extracted with acetonitrile and milk was extracted with acetone. Co-extractives were removed using liquid partitioning and charcoal column procedures described in the carbamate method. Coumaphos and its oxygen analog were determined by using a high performance liquid chromatograph equipped with a fluorescence detector. Recovery studies were performed for the 2 compounds at levels of 0.01 and 0.10 ppm in eggs and 0.01 and 0.02 ppm in milk. Overall average recovery was 100% (range 95-109%). In a trial of the method by another laboratory, the recovery of coumaphos and its oxygen analog from milk averaged 87 and 96%, respectively. Data are presented on the capillary gas chromatographic/mass spectrometric confirmation of coumaphos residues.

Optimized liquid-chromatographic method for fluorometric determination of urinary delta-aminolevulinic acid in workers exposed to lead.

1987 ◽  
Vol 33 (9) ◽  
pp. 1665-1667 ◽  
Author(s):  
K Tomokuni ◽  
M Ichiba ◽  
Y Hirai ◽  
T Hasegawa
Keyword(s):  
Present Method ◽  
High Performance ◽  
Aminolevulinic Acid ◽  
Colorimetric Method ◽  
High Sensitivity ◽  
Liquid Chromatograph ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Urinary Ala

Abstract We developed a fluorometric method for determining delta-aminolevulinic acid (ALA) in urine of lead workers. A high-performance liquid chromatograph (HPLC) equipped with a fluorescence HPLC monitor is used. The detection limit for aqueous ALA is 20 micrograms/L (15 pmol of ALA in the 100-microL sample). The working linear range of urinary ALA concentration was 0.1 to 100 mg/L. In 25 lead-exposed workers, ALA values by the present method for urine correlated well with those obtained by a conventional colorimetric method (r = 0.996). The advantage of the present method for micro-determination of urinary ALA is its high sensitivity.

Quantitative Analysis of 5-Hydroxymethylfurfural in Linezolid Injection by High Performance Liquid Chromatography

2020 ◽  
Vol 16 (8) ◽  
pp. 1059-1067
Author(s):  
Jéssica Maurício Batista ◽  
Christian Fernandes
Keyword(s):  
High Performance ◽  
Potassium Phosphate ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Official Method ◽  
Ph Variation ◽  
Drug Products ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Background: Linezolid is a synthetic broad-spectrum antibacterial belonging to the class of oxazolidinones. Linezolid for intravenous infusion is isotonized with dextrose. In acidic environment, the dehydration of dextrose produces furan derivatives, 5-hydroxymethylfurfural (5-HMF) being the main one. The determination of this degradation product is of fundamental importance, since there is evidence it is cytotoxic, genotoxic, mutagenic and carcinogenic. However, there is no official method for the determination of 5-HMF in drug products. Objective: The aim of this study was to develop and validate a high performance liquid chromatographic method to quantify 5-HMF in injection of linezolid. Methods: The chromatographic separation, after optimization, was performed on C18 (150 x 4.6 mm, 5 μm) column. Mobile phase was composed of 14 mM potassium phosphate buffer pH 3.0 ([H+] = 1.0 x 10-3) and methanol in gradient elution at 1.0 mL min-1. The injection volume was 10 μL and detection was performed at 285 nm. Results: The method was optimized and validated, showing selectivity, linearity in the range from 0.075 to 9.0 μg mL-1, precision (RSD ≤ 2.0%), accuracy (mean recovery of 100.07%) and robustness for temperature and pH variation. Conclusion: The method was shown to be adequate to determine 5-HMF in injection containing linezolid in routine analysis.

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