Národní úložiště šedé literatury Nalezeno 3 záznamů.  Hledání trvalo 0.01 vteřin. 
Hollow-fibre Based Microextraction and Voltammetric Determination of Vanillylmandelic Acid
Hrdlička, Vojtěch ; Barek, J. ; Navrátil, Tomáš
New method of liquid/liquid/liquid hollow fibre based microextraction of vanillylmandelic acid coupled with voltammetric determination is being developed. Selected liquid membranes based on alcohols, aliphatic hydrocarbons and esters were tested. Highest enrichment factor of 2.52 after 30 minutes of extraction was obtained using propyl benzoate, RSD = 18.2 % (n=5). Mechanically and cathodically pretreated (-1000 mV vs. Ag/AgCl/3M KCl, 15 s) boron doped diamond electrode in a miniaturized arrangement was used for DPV determination. LOD = 1.2 micromol/l, RSD = 5.9% (n=10) for a 10 microl extract.
Supported Liquid Membranes for Hollow-Fibre Based Microextraction and Voltammetric Determination of Neuroblastoma Biomarkers
Hrdlička, Vojtěch ; Barek, J. ; Navrátil, Tomáš
Novel method of three phase hollow fibre based liquid/liquid/liquid microextraction coupled\nwith voltammetric determination of clinical biomarkers homovanillic and vanillylmandelic\nacid is being developed. Wide variety of water-immiscible supported liquid membranes\n(SLMs) were tested. Highest enrichment factors were obtained using butyl benzoate as SLM.\nEnrichment factors for 30 min HF-LPME were 3. 0.74 for HVA and 5. 0.45 for VMA,\nrespectively. Repeatability of HF-LPME of microM HVA or VMA was 19.0% for HVA and\n7.9 % for VMA (n=5), respectively.
Possibilities of Hollow Fiber Microextraction and Voltammetric Detection of Homovanillic acid
Hrdlička, V. ; Barek, J. ; Navrátil, Tomáš
The contribution deals with hollow fiber liquid phase microextraction (HF-LPME) of homovanillic acid (HVA) and its subsequent voltammetric detection. In HF-LPME, HVA is extracted from acidic sample through thin supported liquid membrane into basic aqueous acceptor solution. Since common electrode materials such as gold, platinum or glassy carbon are only able to detect HVA under acidic or neutral conditions, a new method was developed, utilizing silica gel modified carbon paste electrode (CPE). Reached limit of detection in a 10 μL drop of the HVA extract of pH 13 was 1·10-5 mol L-1.

Chcete být upozorněni, pokud se objeví nové záznamy odpovídající tomuto dotazu?
Přihlásit se k odběru RSS.