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.

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.

scholarly journals Simultaneous Determination of Potassium Clavulanate and Cefixime in Synthetic Mixtures by High-Performance Liquid Chromatography

2008 ◽  
Vol 91 (4) ◽  
pp. 744-749 ◽  
Author(s):  
Islam Ullah Khan ◽  
Shahzad Sharif ◽  
Muhammad Ashfaq ◽  
Muhammad Nadeem Asghar
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
High Sensitivity ◽  
High Performance Liquid Chromatographic ◽  
Synthetic Mixture ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Potassium Clavulanate ◽  
Liquid Chromatographic

Abstract A simple, precise, and sensitive high-performance liquid chromatographic method was developed and validated for the simultaneous determination of potassium clavulanate and cefixime in synthetic mixture form. The analytes were separated on a C18 column by using 0.03 M disodium hydrogen phosphate buffer (pH 6.5)methanol (84 + 16, v/v) as the mobile phase with detection at 220 nm. The method exhibited high sensitivity and good linearity in the concentration ranges of 12.562.5 and 20100 g/mL for potassium clavulanate and cefixime, respectively. The total run time for the 2 components was <8 min, and the average recovery was >101.5 with a relative standard deviation of <1.0. The proposed method was validated according to guidelines of the International Conference on Harmonization by evaluation of linearity, recovery, selectivity, robustness, limits of detection and quantitation, and within- and between-day precision. The results obtained for the synthetic mixture show that the method is highly precise and accurate for the simultaneous determination of potassium clavulanate and cefixime.

A new enzymic determination of guanidinoacetic acid in urine.

1987 ◽  
Vol 33 (3) ◽  
pp. 394-397 ◽  
Author(s):  
Y Shirokane ◽  
M Utsushikawa ◽  
M Nakajima
Keyword(s):  
High Performance ◽  
Colorimetric Method ◽  
High Performance Liquid Chromatographic ◽  
Great Decrease ◽  
Guanidinoacetic Acid ◽  
Liquid Chromatographic Method ◽  
Analytical Recovery ◽  
Liquid Chromatographic ◽  
Centrifugal Ultrafiltration

Abstract We developed and evaluated a colorimetric method for enzymic determination of guanidinoacetic acid (GAA) in urine. Endogenous urinary urea was first eliminated by urease (EC 3.5.1.5), and the added urease was then removed from the sample by centrifugal ultrafiltration. GAA in the ultrafiltrate was subsequently hydrolyzed by guanidinoacetate amidinohydrolase (EC 3.5.3.2) to glycine and urea. The latter substance produced an orange chromogen reacting with o-phthalaldehyde and N-(1-naphthyl)-N'-diethylethylenediamine, the absorbance of which at 465 nm was linearly related to concentrations as high as 200 mg/L for standard solutions of GAA. Analytical recovery of GAA added to urine ranged from 94 to 112% (mean 101%) and the within-run and between-run precision (CVs) of the method for the urinary GAA determination averaged 2.2 and 3.5%, respectively. Results correlated well (r = 0.983) between the present method and a high-performance liquid chromatographic method. The proposed method is accurate and simple. We saw a great decrease in urinary GAA of patients with suspected or proven renal insufficiency as compared with that of healthy volunteers.

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