The potentiometric titratrion of aluminum and gallium with tetraphenylborate

Analytical and Bioanalytical Chemistry, Oct 2004

Walter S. Selig

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The potentiometric titratrion of aluminum and gallium with tetraphenylborate

The potentiometric titratrion of aluminum and gallium with tetraphenylborate* Walter S. Selig 0 1 0 Division of Gastroenterology and Hepatology, Medizinische Hochschule Hannover , Podbielskistrasse 380, D-3000 Hannover 51, Federal Republic of Germany 1 Lawrence Livermore National Laboratory, University o f California , P. O. Box 808, Livermore, CA 94550 , USA Various cations have previously been determined as their oxonium complexes by potentiometric titration vs. tetraphenylborate (TPB). This includes the alkaline earth metals [1], the rare earth elements [2], and lead [2, 3]. Some of these elements can, in fact, be sequentially estimated [1, 2]. With the exception of lead, these elements are in group IIA or IIIB of the periodic table of the elements. We now report that aluminum and gallium, in group I I I A of the periodic table, can similarly be determined. The oxonium complexes were formed by addition of polyethylene glycol (PEG) of average molecular weight 20,000, and were potentiometrically titrated with a 0.05 tool/1 TPB solution. - * Work performed under the auspices of the U. S. Department of Energy by the Lawrence Livermore National Laboratory under contract number W-7405-ENG-48 Ion-exchange high-performance liquid chromatographic determination of leukotrienes after prel column derivatisation with o-phthal~aldehyde Ionen-Austauscher-HPLC-Bestimmung yon Leukntrienen nach Vors~iulen-Derivatisierung mit o-Phthaldialdehyd Introduction Cysteinyl leukotrienes LTC4, LTD4 and LTE4 are endogenous mediators in anaphylactie and inflammatory reactions [I, 2]. The increasing interest in the biochemistry of the leukotrienes has necessitated the development of sensitive methods for the determination of these metabolites. Reversed-phase high-performance liquid chromatography (HPLC) with detection by UV, radioactivity and fluorescence are the most widely used chromatographic methods for the determination of leukotrienes [ 3 - 7 ]. We have developed a HPLC method for the determination of LTC~, LTD4, and LTE4 using an ion-exchange column and pre-column derivatization with o-phthaldialdehyde. Experimental Reagents and materials. Cysteinyl leukotrienes LTC4, LTD4, and LTE~ were purchased from Paesel (Frankfurt, FRG) and used as received, o-Phthaldialdehyde (OPA) and ammonium acetate were obtained from Fluka (Neu-Ulm, FRG). 2-Mercaptoethanol was purchased from Schuchardt (Mfinchen, FRG). Methanol for HPLC and all other chemicals were from Merck (Darmstadt, FRG). All reagents were of the highest quality available and were stored as recommended. The column (200 mm x 4.6 mm LD.) packed with an ion-exchange material, 1005NH2 Nucleosil, was obtained from Macherey-Nagel (Diiren, FRG). 1. Selig WS ( 1986 ) Fresenius Z Anal Chem 325 : 616 2. Selig WS ( 1988 ) Microchem J 37:155 3. Xiang Y , Yang B , Liu M ( 1985 ) Huaxue Xuebao 43 :1203; through ( 1986 ) Chem Abstr 104:179259g 4. Setig WS ( 1986 ) Microchem J 34:148

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Walter S. Selig. The potentiometric titratrion of aluminum and gallium with tetraphenylborate, Analytical and Bioanalytical Chemistry, 2004, 369-369, DOI: 10.1007/BF00468819