Anna Piasta

New procedure of selected biogenic amines determination in wine samples by HPLC

A new procedure for determination of biogenic amines (BA): histamine, phenethylamine, tyramine and tryptamine, based on the derivatization reaction with 2-chloro-1,3-dinitro-5-(trifluoromethyl)-benzene (CNBF), is proposed. The amines derivatives with CNBF were isolated and characterized by X-ray crystallography and (1)H, (13)C, (19)F NMR spectroscopy in solution. The novelty of the procedure is based on the pure and well-characterized products of the amines derivatization reaction. The method was applied for the simultaneous analysis of the above mentioned biogenic amines in wine samples by the reversed phase-high performance liquid chromatography. The procedure revealed correlation coefficients (R(2)) between 0.9997 and 0.9999, and linear range: 0.10-9.00 mg L(-1) (histamine); 0.10-9.36 mg L(-1) (tyramine); 0.09-8.64 mg L(-1) (tryptamine) and 0.10-8.64 mg L(-1) (phenethylamine), whereas accuracy was 97%-102% (recovery test). Detection limit of biogenic amines in wine samples was 0.02-0.03 mg L(-1), whereas quantification limit ranged 0.05-0.10 mg L(-1). The variation coefficients for the analyzed amines ranged between 0.49% and 3.92%. Obtained BA derivatives enhanced separation the analytes on chromatograms due to the inhibition of hydrolysis reaction and the reduction of by-products formation.

Simultaneous determination of selected biogenic amines in alcoholic beverage samples by isotachophoretic and chromatographic methods.

A simple and useful method for the determination of biogenic amines in beverage samples based on isotachophoretic separation is described. The proposed procedure permitted simultaneous analysis of histamine, tyramine, cadaverine, putrescine, tryptamine, 2-phenylethylamine, spermine and spermidine. The data presented demonstrate the utility, simplicity, flexibility, sensitivity and environmentally friendly character of the proposed method. The precision of the method expressed as coefficient of variations varied from 0.1% to 5.9% for beverage samples, whereas recoveries varied from 91% to 101%. The results for the determination of biogenic amines were compared with an HPLC procedure based on a pre-column derivatisation reaction of biogenic amines with dansyl chloride. Furthermore, the derivatisation procedure was optimised by verification of concentration and pH of the buffer, the addition of organic solvents, reaction time and temperature. Graphical Abstract

Application of ion chromatography for the determination of biogenic amines in food samples

Ion chromatography procedure for the simultaneous determination of histamine, tyramine, phenylethylamine, cadaverine and putrescine in different food samples is described. The simple procedure based on isocratic elution, 5 mM HNO3 without organic modifier as mobile phase and conductometric detection without suppression was proposed and discussed in details. The linearity of the tested procedure was between 0.5–5 and 5–100 mg/L, average recoveries for the standard solutions of amines varied between 98–100%, whereas in standard addition method between 96–99%, that indicated acceptable accuracy of the discussed method. The satisfactory reproducibility was proved by values of coefficient of variations (CV) in the range 0.2–5.0% for all tested food samples. The proposed method reveals a number of advantages: fast elution of analytes without mobile phase conductivity suppression, lack of derivatization step, simple sample preparation and environmentally friendly character.

Optimization of Capillary Isotachophoretic Method for Histidine Determination in Protein Matrices

The capillary isotachophoretic method was optimized and used for histidine determination in food samples. The optimum conditions for histidine separation and determination were found on the experimental conditions such as: selectivity, separation speed, pH, concentration of the leading and terminating electrolytes, and electroosmotic flow additives. The optimum electrolytes composition [leading electrolyte: 7 mM NH4OH + 15 mM 2-(N-morpholino)ethanesulfonic acid + 1% hydroxyethylcellulose; pH = 6.10 and terminating electrolyte: 15 mM aminocaproic acid +5 mM acetic acid +40% methanol; pH = 5.10] and conditions of analysis were adopted for histidine determination in food samples (meat and fish products). The proposed electrolyte system was characterized by linearity (10–100 and 100–430 mg · L−1 with R2 = 0.9976 and 0.9991), accuracy (99.5% and 98%), intra-assay of the relative step height (1.40% for standard and 3.20% for food samples analysis), inter-assay of the relative step height (3.65% and 6.30%) and satisfactory quantification and detection limits. The obtained results were compared to a chromatographic method (reversed-phase (RP)-HPLC) for determination of histidine. The average concentrations of histidine in the samples assayed by both methods were statistically comparable. It should be noted that the proposed histidine determination method can be considered as a contribution to Green Analytical Chemistry.

Application of 3,5-bis-(trifluoromethyl)phenyl isothiocyanate for the determination of selected biogenic amines by LC-tandem mass spectrometry and 19F NMR

3,5-Bis-(trifluoromethyl)phenyl isothiocyanate, was used as a convenient reagent for the derivatization of histamine, tyramine, tryptamine and 2-phenylethylamine, which eliminates the purification step. The obtained derivatives were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Additionally, the total amount of these amines was determined by 19F nuclear magnetic resonance analysis. The procedures were optimized and validated for linearity, limit of detection and quantification, intra- and inter-day precision and recovery resulting in good reproducibility and accuracy. The reagent was applied for determination of the above mentioned biogenic amines in beverages, and permitted an undemanding separation and determination of the derivatives. Moreover, it is a convenient reagent for analysis of the total amine content by quantitative 19F NMR.

The influence of pH and selected cations on the spectrofluorometric determination of oxytetracycline hydrochloride

The spectrofluorometric method for the oxytetracycline hydrochloride in pure and in veterinary products Tetrox and Oxymed 50 determination is described. The influence of pH solution and presence selected cations on fluorescence intensity were studied too. It was ascertained that the highest fluorescence intensity take place at pH=9. Moreover, the quenching of fluorescence intensity was observed at presence Ca2+, Al3+ and Fe3+ in contrast to Mg2+ which caused increasing of intensity. The obtained recovery (97.23±0.12% for Tetrox and 95.21±0.10% for Oxymed 50) values meet the European Pharmacopoeia requirement. Moreover, the relative standard deviation (RSD) was below 0.23% confirmed high precise of the method. The statistical test (t-Student and F-Snedecor) used for comparison spectrofluorometric and chromatographic methods pointed that they are comparable in respect of precision but not of accuracy.