University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Human

Classification: Cell -> erythrocyte -> human

Citations 7

"Determination Of Organolead Compounds And Of Chromate Beside Chromium(III)"
Microchim. Acta 1992 Volume 109, Issue 1-4 Pages 137-140
Bernd Neidhart and Christoph Tausch

Abstract: The pre-concentration. and determination of ionic alkyl-lead compounds in surface water and human urine and tetra-alkyl-lead compounds in ambient air are described. Preconcentration and cleanup steps were followed by HPLC separation. Ionic species were pre-concentrated by solid-phase extraction; detection was performed online. The alkyl-lead species were eluted from the HPLC column, partially de-alkylated by iodine solution to form dialkyl-lead species and detected as PAR [4-(2-pyridylazo)resorcinol] complexes after the reduction of excess iodine with thiosulfate and adjustment to pH 9 to 10. Difficulties in the validation of trimethyl-lead and dimethyl-lead in some matrices are discussed. A Cr(VI) speciation method consisting of selective biosampling using human erythrocytes and gas-furnace AAS and reversed flow injection analysis is described.
tetraalkyllead Chromium(VI) Spectrophotometry Reverse Speciation

"Assay Of Biological Thiols By A Combination Of High Performance Liquid Chromatography And Post-column Reaction With 6,6'-dithiodi(nicotinic Acid)"
Anal. Biochem. 1984 Volume 138, Issue 1 Pages 95-98
Junko Nishiyama and Toyo Kuninori

Abstract: Thiols were separated by HPLC on a reversed-phase column (25 cm x 4.6 mm) packed with Fine Sil C18-10, with, as mobile phase, 33 mM KH2PO4 adjusted to pH 2.2 with H3PO4 or 33 mM sodium phosphate of pH 6.8; detection was by post-column derivatization with 6,6'-dithiodi(nicotinic acid) and measurement of the absorbance of the released 6-mercaptonicotinic acid at 344 nm. A comparison was made with post-column derivatization with 5,5'-dithiobis-(2-nitrobenzoic acid). Cysteine, cysteamine, homocysteine, glutathione and penicillamine were determined (detection limit 0.1 nmol); ergothioneine, 2-thiouracil and thiolhistidine could be separated but not determined. The method was applied to the assay of glutathione in human erythrocytes and in E. coli.
Cysteine Cysteamine Homocysteine Glutathione Penicillamine HPLC Spectrophotometry Post-column derivatization

"Flow-through Analysis Of Glutathione In Human Erythrocytes With An Amperometric Biosensor"
Anal. Lett. 1994 Volume 27, Issue 1 Pages 15-27
Compagnone, D.;Federici, G.;Scarciglia, L.;Palleschi, G.

Abstract: Glutathione oxidase in 0.1 M phosphate buffer of pH 6.5 (buffer A) was bonded to a pre-activated Immobilon-AV membrane as described by Villarate et al. (Talanta, 1991, 38, 49). The sensor was assembled by placing the membrane in contact with the gas-permeable membrane of a Clark oxygen electrode then mounted in a flow-through cell. Buffer A was pumped through the cell until a constant current from the reduction of O2 at -0.68 V vs. Ag/AgCl was reached. Sample solution was then injected and the current change was recorded. Calibration graphs were linear for 10^-1000 µM-glutathione with a detection limit of 5 µM. At 0.1 mM, the RSD was 4.5% (n = 20) with response time of 1 min. The method was used to determine glutathione in erythrocytes. Twenty samples were analyzed by this method and by a spectrophotometric method; the correlation coefficient was 0.975. The recovery of 1-3 mM glutathione added to haemolysed erythrocytes was 95-103%.
Glutathione Electrode Electrode Spectrophotometry Sensor Amperometry

"Determination Of Thiamine And Its Phosphate Esters In Human And Rat Blood By High Performance Liquid Chromatography With Post-column Derivatization"
J. Chromatogr. A 1985 Volume 332, Issue 1 Pages 181-188
Mieko Kimura and Yoshinori Itokawa

Abstract: Blood, erythrocytes and plasma were deproteinized with aqueous 10% trichloroacetic acid. After centrifugation, the supernatant solution were analyzed by HPLC on a µBondapak C18 column (25 cm x 4 mm) with 0.2 M NaH2PO4 in aqueous 0.3% acetonitrile as the mobile phase (1.0 mL min-1); the eluates were subjected to post-column derivatization with 0.1% of K3Fe(CN)6 in aqueous 15% NaOH and spectrofluorimetric detection at 450 nm (excitation at 375 nm). The detection limit for thiamine and its phosphate esters was 30 fmol and recoveries were 95.0 to 100.2%. The calibration graphs were rectilinear for 50 to 200 fmol.
Thiamine Thiamine triphosphate Thiamine monophosphate HPLC Fluorescence Post-column derivatization

"Determination Of Guanine And Its Nucleosides And Nucleotides In Human Erythrocytes By High Performance Liquid Chromatography With Post-column Fluorescence Derivatization Using Phenylglyoxal Reagent"
J. Chromatogr. B 1994 Volume 654, Issue 1 Pages 19-24
Sayuri Yonekura, Masatake Iwasaki, Masaaki Kai and Yosuke Ohkura*

Abstract: Erythrocytes from 5 mL of blood were homogenized in 400 µL of water, 100 µL of 3 M HClO4 and 20 µL of 9-ethylguanine solution (200 nmol/ml; internal standard), centrifuged, the supernatant was adjusted to pH 6 with 1 M KHCO3 and passed through an ODS mini-cartridge. The first eluate (20-50 µL) was analyzed by HPLC on a column (15 cm x 4.6 mm i.d.) of TSKgel ODS-120T (5 µm) with gradient elution (1 ml/min) from 0-20% methanol in 10 mM tetra-n-propylammonium phosphate of pH 6/50 mM Na2PO4 buffer of pH 6/H2O (17:20:63 to 17:20:43) with detection at 254 nm and post-column derivatization at 80°C with 60 mM phenylglyoxal in methyl cellosolve/H2O (1:9; 0.5 ml/min) in a reaction coil (3 m x 0.5 mm i.d.) for fluorescence detection at 515 nm (excitation at 365 nm). The calibration graphs for guanine and its nucleosides and nucleotides were linear from 20-500 pmol and the detection limits were 3.2-10 pmol/20 µL. No interfering compounds were identified. The recoveries of GTP and GDP were 90-100%. No RSD are given.
Guanine Nucleosides, guanine Nucleotides, guanine HPLC Fluorescence Interferences Post-column derivatization

"High Performance Liquid Chromatographic Determination Of Ribonucleotides By Post-column Derivatization Involving Oxidation Followed By Fluorescence Reaction And Its Application To Human Erythrocyte Samples"
Anal. Sci. 1990 Volume 6, Issue 4 Pages 519-522
Y. UMEGAE, H. NOHTA and Y. OHKURA

Abstract: Ribonucleotides such as ATP and ADP were separated on a column (25 cm x 4.6 mm) of TSK gel ODS-80 (5 µm) and converted into fluorescent derivatives by reaction with 1,2-bis-(4-methoxyphenyl)ethylenediamine in acidic medium after oxidation with NaIO4. The detection limits were 14 to 67 pmol injected. The method was applied to human erythrocytes, and showed good sensitivity and high selectivity.
Ribonucleotides HPLC Fluorescence Post-column derivatization Column Detection limit Selectivity Sensitivity Heated reaction

"The Utilization Of Intravenously Infused Pyridoxine In Humans"
Clin. Chim. Acta 1994 Volume 229, Issue 1-2 Pages 27-36
Janos Zempleni* and Werner Kübler

Abstract: Plasma (70 µL) was mixed with 15 µL of 10 M HCl and 500 µL was transferred onto a membrane and centrifuged at 4°C for 35 min at 17 000 g. Before analysis the sample was mixed with 0.1 M sodium acetate of pH 3.8 (1:1). Washed erythrocytes (300 µL) were mixed with 300 µL of 0.1 M sodium acetate buffer of pH 3.8. Trichloroacetic acid (200 µL, 20%) was added with centrifugation for 5 min at 12 000 g then 350 µL of the supernatant was mixed with 700 µL of sodium acetate buffer. A 100 µL portion was analyzed on a 5 µm RP 18 column (12.5 cm x 4 mm i.d.) equipped with a pre-column (4 x 4 min i.d.) with gradient elution (1.5 ml/min) with 0.03 M KH2PO4/4 mM octanesulfonic acid, pH 2.7/methanol (details given) and post-column derivatization with 0.5 M K2HPO4 and 10 µL/ml of 37% NaHSO3 (pH 7.5, flow rate 0.07 ml/min). Detection was at 400 nm (excitation at 330 nm). The method allowed the determination of 4-pyridoxic acid, pyridoxal, pyridoxal 5'-phosphate, pyridoxamine, pyridoxamine 5'-phosphate and pyridoxine. Intra- and inter-run RSD (n = 10) were 2.8-7.2 and 6.2-10.3%, respectively. Detection limits were 10 nM and recoveries were 94.2-96.5%.
Pyridoxal Pyridoxal phosphate Pyridoxamine 4-Pyridoxic acid Pyridoxine HPLC Clinical analysis