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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Skin

Classification: Biological tissue -> skin

Citations 2

"Trace Analysis Of Benzalkonium Chloride On Skin By Flow Injection Ion Spray Mass Spectrometry-mass Spectrometry"
Analyst 1998 Volume 123, Issue 3 Pages 489-491
Shoji Kawakami, Robert H. Callicott and Nan Zhang

Abstract: A method for the anal. of trace-level benzalkonium chloride has been established using flow injection ion spray mass spectrometry-mass spectrometry with multiple reaction monitoring. Quantification was carried out using an external standard based on peak area summation of each benzalkonium ion (C8, C10, C12, C14, C16 and C18) in the mass spectra. The multiple reaction monitoring technique provides additional specificity for identification and quantification. The quantification linear dynamic range was found to be 5.0-100.0 ng mL-1, the correlation coefficient >0.999, and the detection limit 1.2 ng mL-1. The method was applied to quantify benzalkonium chloride on skin, which was sampled with a D-SQUAME tape from skin surface and extracted from the tape with methanol.
Benzalkonium chloride Mass spectrometry Sample preparation

"Rapid Microdetermination Of Hydroxyproline In Biomedical Samples By Flow Injection Analysis Using Cysteine As An Antioxidant"
Anal. Sci. 1990 Volume 6, Issue 1 Pages 39-44
K. UCHIDA, M. TOMODA, T. SHIBATA, S. IKEUCHI, T. HASEBE, T. MIWA, T. NOMOTO, K. FUKUSHIMA, S. SAITO and S. INAYAMA

Abstract: Tissue samples are hydrolyzed with 6 M HCl, the mixtures are freeze-dried, and the residues are dissolved in 0.01 M cysteine. Portions are injected into a stream of chloramine T solution (0.7 g L-1 in borate buffer of pH 8.7). Passage through a heating coil at 100°C causes hydroxyproline (I) to be oxidized and decarboxylated to pyrrole. Treatment with a solution of Ehrlich reagent (4-dimethylaminobenzaldehyde) in 10% H2SO4 and 10% Triton X-100 gives a colored product, which is detected at 560 nm. The calibration graph is rectilinear in the range 1 to 80 µg mL-1 of I. Optimization experiments are described especially for concentration. of chloramine T (oxidant) and cysteine (color stabilizer). The method, which avoids use of organic solvents, allows 100 samples to be analyzed in ~5 h. Recoveries of I are 94.8 to 103.7%. Results agreed well with those from a batch method.
Hydroxyproline Spectrophotometry Buffer pH Triton X Calibration Optimization Heated reaction Surfactant