Leaching from the stratum corneum does not explain the previously reported elevated potassium ion concentration in sweat

Author(s):  
Michael J. Buono ◽  
Michael Stone ◽  
Daniel T. Cannon

AbstractThe purpose of this study was to determine if KTwelve (six female, six male) healthy volunteers participated in this study. After thorough skin cleansing and preparation with isopropyl alcohol and high-performance liquid chromatography-grade distilled water, three sites were chosen and a 50 μL drop of artificial sweat was pipetted directly onto the skin. The artificial sweat had a [KThe mean (±SD) [KThese results do not support the hypothesis that significant K

1996 ◽  
Vol 59 (8) ◽  
pp. 898-900 ◽  
Author(s):  
Mª JOSÉ BARRIOS ◽  
Mª JESÚS GUALDA ◽  
J. M. CABANAS ◽  
L. M. MEDINA ◽  
R. JORDANO

Thirty-five samples of commercial cheeses, 9 fresh, 9 semicured or semiripened and 17 ripened made with different types of milk (cow, ewe, goat and mixtures of milk of various species) produced in the South of Spain were analyzed for the presence of aflatoxin M1 (AFM1) by high-performance liquid chromatography, In 16 of the 35 samples (45.71%) the presence of AFM1 was detected in concentrations ranging between 20 and 200 ng/g of cheese, In the positive cases, the mean levels of AFM1 were 105.33 ng/g in ripened cheeses, 73.80 ng/g in semiripened cheeses and 42.60 ng/g in fresh cheeses.


2000 ◽  
Vol 9 (1) ◽  
pp. 17-22 ◽  
Author(s):  
N. JEPPSON ◽  
G. XIANGQUN

The contents of kaempherol, quercetin and L-ascorbic acid in sea buckthorn berries were measured at different maturation stages using High Performance Liquid Chromatography (HPLC) methods. The content of ascorbic acid decreased over time with significant differences between sampling dates for the five cultivars studied. The mean decrease was 25% in 19 days, from 1.48 to 1.10 g kg-1. Quercetin decreased whereas kaempherol increased during maturation. Among three studied cultivars, the decrease in quercetin was significant (from 0.028 to 0.014 g kg-1) in 'Otradnaja', where as the increase (from 0.012 to 0.016 g kg-1) in kaempherol was significant in the others two, 'Prozratnaja' and 'Gibrid Pertjik'.;


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Mohammed Moniruzzaman ◽  
Chua Yung An ◽  
Pasupuleti Visweswara Rao ◽  
Mohammad Nurul Islam Hawlader ◽  
Siti Amirah Binti Mohd Azlan ◽  
...  

The aim of the present study was to characterize the phenolic acids, flavonoids, and antioxidant properties of monofloral honey collected from five different districts in Bangladesh. A new high performance liquid chromatography (HPLC) equipped with a UV detector method was developed for the identification of the phenolic acids and flavonoids. A total of five different phenolic acids were identified, with the most abundant being caffeic acid, benzoic acid, gallic acid, followed by chlorogenic acid and trans-cinnamic acid. The flavonoids, kaempferol, and catechin were most abundant, followed by myricetin and naringenin. The mean moisture content, total sugar content, and color characteristics of the honey samples were 18.36 ± 0.95%, 67.40 ± 5.63 g/100 g, and 129.27 ± 34.66 mm Pfund, respectively. The mean total phenolic acids, total flavonoid content, and proline content were 199.20 ± 135.23, 46.73 ± 34.16, and 556.40 ± 376.86 mg/kg, respectively, while the mean FRAP values and DPPH radical scavenging activity were 327.30 ± 231.87 μM Fe (II)/100 g and 36.95 ± 20.53%, respectively. Among the different types of honey, kalijira exhibited the highest phenolics and antioxidant properties. Overall, our study confirms that all the investigated honey samples are good sources of phenolic acids and flavonoids with good antioxidant properties.


2005 ◽  
Vol 78 (4) ◽  
pp. 674-681 ◽  
Author(s):  
Elizabeth K. Abraham ◽  
P. Ramesh ◽  
R. Joseph ◽  
P. V. Mohanan ◽  
V. M. Remakumari

Abstract The release of zinc dialkyldithiocarbamates from a batch of surgical gloves into the sweat of human subjects was studied. Healthy volunteers from both sexes were asked to don the gloves on both hands for 1 h. The identification and estimation of dithiocarbamate residues released into the sweat were carried out using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The thin layer chromatogram showed that zinc diethyldithiocarbamate (ZDEC) accelerator residues were released into the sweat of volunteers. The estimation by high performance liquid chromatography revealed that the amount of ZDEC released varied among the human subjects despite using the same brand of glove. The effect of sweat rate and pH on the amount of ZDEC released into hand sweat was investigated. The results indicated that it may not be possible to derive a relationship between the sweat-extractable ZDEC and sweat rate or pH of hand sweat. The dithiocarbamate release was studied in the laboratory using a physiologically simulated medium, namely, artificial sweat at different pH levels. The glove was filled with artificial sweat and extracted for 1 h at 37 °C. It was found that amount of artificial sweat-extractable ZDEC varied with changes in pH of artificial sweat. Lack of a clear relationship between the sweat-extractable ZDEC and sweat rate or pH of hand sweat indicated that factors such as hand exercise, glove-fit, etc., may also be considered when simulating actual use conditions in vitro.


Author(s):  
Roger N Johnson ◽  
Russell Sargon ◽  
Gerald Woollard ◽  
James Davidson

Background: Sirolimus is an immunosuppressive agent used after organ transplantation. Monitoring its concentration is clinically relevant, but current methods of measurement using high-performance liquid chromatography (HPLC) are demanding. An immunoassay that uses readily available equipment offers a more convenient alternative. Methods: Blood specimens from transplant patients were assayed for sirolimus by an existing HPLC method with ultraviolet (UV) detection and by the Abbott microparticle enzyme immunoassay (MEIA). Within-run and between-day precision was assessed with duplicate analyses. Accuracy was assessed by comparison of results from the MEIA and HPLC assays, and from recovery experiments. Specificity was tested in specimens from patients taking alternative immunosuppressants. Results: Using specimens with sirolimus concentrations between 3.3 and 39.3 µg/L, within-batch and between-batch coefficients of variation (CVs) were 6.8% and 6.3%, respectively. Using control specimens with mean concentrations of 4.1, 12.1 and 25.4 µg/L, the respective CVs were 8.6%, 3.1% and 3.8 %. Using a Passing-Bablok regression technique, the regression equation was MEIA = 14; 1.26 x HPLC-1.97; the mean bias was 0.96 µg/L. Specimens from patients on cyclosporin and tacrolimus as the sole immunosuppressant had apparent sirolimus concentrations of <1 µg/L. Conclusion: The MEIA assay for sirolimus provides clinically useful information within an accessible format.


2012 ◽  
Vol 577 ◽  
pp. 69-72 ◽  
Author(s):  
Shu Yu Liu ◽  
Anaerguli Maihemuti

A simple and rapid high performance liquid chromatography (HPLC) assay was developed to identify and measure theβ-sitosterol with chemical course and material applications in jatropha seed oil. The stigmasterol was isolated with a good selectivity by HPLC employing reversed phase C18 columns. The components were separated by mobile phase of methanol-water (99/1, v/v) and detected at 205nm. The quantitation of the stigmasterol was reproducible and the method relative standard deviation is 1.1%. The mean analytical recovery was 96.2%.


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