Julius Kerkay

Separation and Quantitation of Urinary Phthalates by HPLC

Abstract A method was developed for the separation and quantitation of plasticizers and their metabolites from human urine using HPLC, Urine was diluted with an equal volume of water and extracted at pH 2.0 with diethyl ether, The extract was dried, the solvent vacuum stripped, and the residue dissolved in methanol for injection into the chromatograph. A C18 reverse phase column containing 10 μ particles was used for the analysis. Ionic suppression, 0.5% acetic acid in water, at pH 3.0 was used to resolve the acidic components. A step gradient of acetonitri1e:water (containing acetic acid) was used to elute the polar metabolites as well as the non-polar plasticizers. Mass spectrometry was used t o identify the compounds in the HPLC fractions. From the HPLC fractions of the urine extract collected, phthalic acid, MEHP, DEHP and normal urinary constituents (e.g., hippuric and benzoic acid derivatives) were identified

Human Metabolism of Bis(2-ethylhexyl)phthalate

Abstract To study the human metabolism of bis (2-ethylhexyl)-phthalate (DEHP) urine samples were analyzed from non-uremic psoriatic patients, uremic patients undergoing hemodialysis treatments and patients undergoing cardiac bypass surgery using High Performance Liquid Chromatography (HPLC). The urine of dialyzed non-uremic patients contained phthalic acid, mono (2-ethylhexyl) phthalate and bis (2-ethylhexyl) phthalate. Other compounds identified were p-hydroxy benzoic acid, m-hydroxy benzoic acid, o-hydroxy hippuric acid, o-hydroxy benzoic acid and benzoic acid, which may be either diet dependent normal urinary constituents or metabolites of bis (2-ethylhexyl) phthalate. The levels of phthalic acid and bis (2-ethylhexyl) phthalate found in the urine of patients who were on total body oxygenators containing a membrane during cardiac bypass surgery were comparable to levels obtained from non-uremic psoriatic patients. Significant levels of phthalic acid were detected in the urine of the uremic patients stu...

Quantitative Serum Amiodarone Determination by High Performance Liquid Chromatography

Abstract A HPLC method was developed for the separation and quantitation of Amiodarone from serum. Comparison of C18-reverse phase and Si-normal phase chromatography is given. The analysis requires 1 ml serum and is linear to 5000 ng Amiodarone/m1 serum. The preferred C18-reverse phase analysis is a simple, rapid and reliable method for the quantitation of Amiodarone.

Determination of zinc in whole blood, plasma and serum using Zeeman effect flame atomic absorption spectroscopy

Methods are presented for the determination of zinc in whole blood, plasma and serum using Zeeman effect flame atomic absorption spectroscopy and a flame microsampling funnel. Whole blood was diluted 1/25 with 0.10 mol/l hydrochloric acid; plasma and serum were diluted 1/5 with deionized water. Concentrations could be read directly from standards prepared in human blood pools. The within-run relative standard deviation (RSD) was 0.50%, 0.82% and 0.61% for whole blood specimens with concentrations of 4 360 micrograms/l, 5 967 micrograms/l and 8 297 micrograms/l, respectively. The within-run RSD was 2.09%, 1.16% and 0.62% for plasma specimens with zinc concentrations of 442 micrograms/l, 976 micrograms/l and 1 731 micrograms/l, respectively. The within-run RSD was 1.18%, 1.22% and 1.02% for serum specimens with zinc concentrations of 492 micrograms/l, 1 023 micrograms/l and 1 533 micrograms/l, respectively. The detection limit was 3.6 micrograms/l.

Determination of copper in whole blood, plasma and serum using Zeeman effect atomic absorption spectroscopy

Methods are presented for the determination of copper in whole blood, plasma and serum using Zeeman effect flame and furnace atomic absorption spectroscopy. Three flame measurement modes were compared: continuous aspiration, microsampling in the peak height mode and microsampling in the peak area mode. The microsampler/peak area method was the most satisfactory. The precision for the microsampler/peak area method was as follows: the within-run relative standard deviation (RSD) was 1.84% and 1.89% for whole blood specimens with copper concentrations of 983 micrograms/l and 974 micrograms/l, respectively. The within-run RSD was 2.14, 1.66 and 0.87% for plasma specimens with concentrations of 990, 1,467 and 1,963 micrograms/l, respectively. Within-run RSD was 6.64, 2.86 and 1.15% for serum specimens with concentrations of 462, 984 and 2,056 micrograms/l, respectively. The average detection limit for the microsampler/peak area method was 10.3 micrograms/l. Concentrations could be read directly from standards prepared in human whole blood, plasma or serum pools or in a commercial control.

Determination of zinc and copper in urine using Zeeman effect flame atomic absorption spectroscopy

Zinc and copper were determined in urine using polarized Zeeman effect flame atomic absorption spectrophotometry. For the zinc assay, urine was diluted 1/10 with deionized water. Concentrations could be determined by comparison to standards in a salt matrix or in a commercial urine control. The linearity of the assay was 350 micrograms/l, the detection limit was 1.2 micrograms/l and the within-run relative standard deviation (RSD) was 2.08%, 3.06%, 0.71% and 1.29% for specimens with zinc concentrations of 202 micrograms/l, 206 micrograms/l, 1 003 micrograms/l and 1 032 micrograms/l, respectively. The between-run RSD was 2.34% for a mean zinc concentration of 461 micrograms/l. For the copper assay, urine was aspirated directly and concentrations were determined by standard additions. The linearity of the assay was 5 000 micrograms/l, the detection limit was 4.6 micrograms/l and the within-run RSD was 24.49%, 16.10%, 4.00% and 3.19% for specimens with copper concentrations of 9.8 micrograms/l, 11.8 micrograms/l, 50.0 micrograms/l and 50.2 micrograms/l, respectively. The between-run RSD was 8.78% and 4.72% for specimens with copper concentrations of 21.1 micrograms/l and 40.3 micrograms/l, respectively.

Determination of Urinary Bis(2-ethylhexyl)phthalate Levels in Non-uremic Subjects by Gas Chromatography

Abstract In vivo studies of urinary bis(2-ethylhexyl)phthalate (DEHP) levels in dogs and in non-uremic patients undergoing hemodialysis treatments for psoriasis were undertaken. Dogs were divided into 3 groups: Control, Sham-Operated, and Nephrectomized. Each dog received 225 mg DEHP per kilogram body weight via the femoral vein. Each of the non-uremic patients underwent hemodialysis therapy for 4–5 hours once a week for four consecutive weeks to treat their psoriatic condition. Specimens of 2 4 hr urine were collected and analyzed for DEHP by gas chromatography. The detection limit of DEHP in urine is 15 ng/ml. No detectable DEHP was found in the urine of all pre-injection specimens obtained from all three groups of dogs. The total urinary DEHP concentrations for the four day period were found to be 76.1 and 192.2 μg for the Control and the Sham-Operated dogs, respectively. No urine samples could be collected from the Nephrectomized dogs. DEHP levels were found in the 24 hr urine specimens from some of t...

Isolation and Purification of the Down Syndrome Protein

Abstract The presence of the Down syndrome (DS) protein in the sera of individuals is associated with a higher than average risk of parenting a child with Down syndrome. The protein has been determined to be a lipoprotein and is presumably a variant of β-lipoprotein. Isolation of the DS protein is accomplished by means of hydroxylapatite chromatography. Elution of the protein is achieved in 7.5 hours via a 5 phosphate buffer scheme utilizing successively increasing phosphate concentrations while maintaining constant pH. Immunoelectrophoretic and SDS-PAGE techniques have been used to assess the composition of the fraction resulting in the DS protein being obtained with a high degree of purity.

A Crossed Immunoelectrophoretic Technique for the Detection of the Down's Syndrome Protein

Abstract The sera of seventy-one women and twenty-six men of various ages were examined by a two dimensional (crossed) immunoelectrophoresis technique which was modified to detect a protein (the Downs Syndrome protein) originally found in the sera of mothers of trisomy 21 children. The sensitivity of the method is reported to be 0.1 to 1.0 mg/L. Modifications included use of a Tris-Tricine buffer, high voltage in the second dimension, and relatively low antibody concentration to allow easy detection of the Downs Syndrome (DS) protein. Of twenty-eight mothers and twelve fathers of trisomy 21 children, eighteen mothers and five fathers were positive, while of forty-three women and fourteen men having unaffected or no children, only seven women and two men were positive for the DS protein. Since the presence of the Downs Syndrome protein may indicate a propensity for giving birth to a trisomy 21 affected child, this crossed immunoelectrophoretic technique may be used as a screening procedure for the DS pr...

A microcomputer automated recording spectropolarimeter.

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