Tyramine derivatization

Metabolites of biogeiuc amines have also been analyzed by GC-ECD. For the simultaneous analysis of 5-hydroxyindole-3-acetic acid (5-HIAA), homovanillic acid (HVA) and m- and p-hydroxyphenylacetic acid (m-, p-HPAA), (metabolites of 5-HT, DA, and m- and p-tyramine acid respectively) in urine, a simple acidic extraction followed by derivatization with PFPA (derivatizes phenols) and hexafluoroisopropanol (deriva-tizes carboxylic acid groups) has been used (Davis et al., 1982 Baker et al., 1987). 

Hernandez-Jover et al. (72) derived an improved analytical method from the HPLC procedure setup they developed in 1995 (73) for the determination of BAs in fish. The method consists of the extensive extraction with HC104, ion-pair (with sodium octanesulfonate) RP-HPLC separation, postcolumn derivatization with PA/ME, and spectrofluorimetric detection. Determination limits were up to 1.5 mg/kg. In particular, His, Tyr, Phe, Ser (serotonine), Cre (creatinine), Try, Oct (octopamine), Dop (dopamine), Cad, Put, Agm (agmatine), Spm, and Spd were studied in pork and beef meat, fresh, cooked, or ripened. Tyramine, His, Put, Cad, and Try levels were... 

The zig-zag mixer was then used as a pre-column reactor to derivatize biogenic amines such as histamine and tyramine with o-phthaldialdehyde and to detect the corresponding products with micellar electro kinetic chromatography [150]. A separation of four amines, histamine, tyramine, putrescine and tryptamine, was demonstrated in that way. 

Fig. 3. GC-MS selected ion-monitoring trace of pHj] and [ Hg] p-octopamine (as their DTFMB-TMS derivatives) from 50 DUM cells incubated with pHg] p-tyramme (A) Detection of endogenous p-octopamine (mass-to-charge ration 537) (B,C) Deu-terated pHg] p-octopamine (mass-to-charge ratio 542) and pHgjp-octopamine (mass-to-charge ration 543), respectively. These deuterated products must have been synthesized by the DUM cells from [ Hg] p-tyramine, because they are not present m the controls. Int. Std. Internal stan d (PH3] m-octopamine) added at the time of derivatization to allow quantification of amines recovered. The y-axis of the figine represents instrument response in arbitrary units. M/Z Mass-to-charge ratio for the particular 10ns being monitored, which in each case corresponds to the molecular weights of the derivatives of the species present.

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