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A solid-phase extraction method followed by reverse phase high-performance liquid chromatography (RP-HPLC) was optimized and validated for the quantitative determination of tartaric, malic, shikimic, lactic, citric and succinic acids in wine. Solid-phase extraction was carried out with C18 cartridges and extraction recoveries for all acids ranging from 98.3 to 103% were obtained. HPLC separation was performed with isocratic elution on a LiChrosorb RP-18 column (250 × 4.6 mm I.D., 5 µm) protected with the appropriate guard column. The mobile phase was a 5 mM solution of H3PO4 with pH 2.1 at a flow rate of 1 ml/min. Detection of the organic acids was performed at 210 nm. The developed method was validated by checking its linearity, limit of detection (LOD), limit of quantification (LOQ), precision and recovery. The method was applied to the analysis of organic acids in Macedonian red and white wines.Keywords: wine; organic acids; separation; HPLC; validation ВАЛИДАЦИЈА И ПРИМЕНА НА HPLC ЗА АНАЛИЗА НА ОРГАНСКИ КИСЕЛИНИ ВО ВИНО ПО ЦВРСТО-ФАЗНА ЕКСТРАКЦИЈАОптимизиран и валидиран е метод за квантитативна анализа на винска, јаболкова, шикимска, млечна, лимонска и килибарна киселина во вино со цврсто-фазна екстракција следена со реверзно-фазна високо ефикасна течна хроматографија (RP-HPLC). Цврсто-фазната екстракција е изведена со колони C18 и добиениот аналитички принос за сите киселини се движи од 98,3 до 103%. Разделувањето со HPLC е извршено со изократско елуирање на LiChrosorb-ова колона RP-18 (250 × 4,6 mm I.D., 5 µm) користејќи соодветна претколона. Мобилната фаза којашто е употребена за елуирање е раствор од H3PO4 со концентрација 5 mM и pH 2,1 при проток од 1 ml/min. Детекцијата на органските киселини е извршена со следење на апсорбанцата на 210 nm. Развиениот метод е валидиран со проверка на неговата линеарност, осетливост, граница на детекција (LOD), граница на квантификација (LOQ), аналитички принос и прецизност. Методот потоа е применет за анализа на органски киселини во македонски црвени и бели вина.

The abundances of selected elements in different environmental compartments, namely soil, honey, and bee pollen, was determined in this study. For that purpose, sixteen soil and honey samples, and nine pollen samples were taken in the region of Mitrovica, Kosovo. The concentration of elements was measured by ICP-AES and ICP-MS. Pollution level concentrations of Pb, Zn, As, and Cd were observed in soil. The level of soil pollution was estimated by calculating pollution indices. Pb was also observed at high concentrations in honey, as was Cd and Pb in pollen. Pearson’s correlation coefficients revealed mostly weak and moderate correlations of the concentrations of the eight selected elements among the soil, honey, and pollen samples. Several groups of elements with geogenic and anthropogenic origin were identified by hierarchical cluster analysis. The concentrations of selected heavy metals for soil and honey were compared to those in neighboring countries, and those for pollen with samples from Turkey, Serbia, and Jordan.

In this study, a fast, simple, and sensitive analytical method for direct determination of biogenic amines tryptamine, putrescine, histamine, phenylethylamine, tyramine, cadaverine, spermine, and spermidine in wine has been developed and validated. Detection of analytes was performed with ultra-performance liquid chromatography (UPLC) coupled to triple quadruple mass spectrometer (TQ/MS). The calibration curves of all amines were linear with correlation coefficients (R 2 ) ranging from 0.9906 for putrescine to 0.9998 for histamine and 2-phenyethylamine. The accuracy of the method was checked with a standard addition method, showing good accuracy, repeatability, and reproducibility (RSD < 10%). The limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.50 to 30 μg/L and 1.50 to 90 μg/L, respectively, for all amines. The validated method was applied to detect and quantify biogenic amines in Macedonian red and white wines. Higher concentration of amines was observed in red wines (5797 μg/L, on average) compared to the white wines (1485 μg/L, on average).

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The intense mineral extraction in mining areas during the last several decades has produced a large amount of waste material and tailings, which release toxic elements to the environment. The aim of the study was to determine in two vertical profiles/sections (1 and 2) the heavy metal contents of samples derived from six samples, three from each section located in the porphyry copper mine Buchim area, Republic North Macedonia. The results have been compared to new Dutchlist (DL) and Kabata-Pendias (KP) standards and the following was concluded: As values ranged 14.985÷60.131 mg kg-1 with 4 samples above the target value of the DL (29 mg kg-1 As) and 6 above standard values given in KP value (5 mg kg-1 As), in that context Co values ranged 11 ÷57 mg kg-1 with 6 values above the target value of the DL (9 mg kg-1 Co) and 5 above standard values given in KP value (12 mg kg-1 Co), Cr with range 29.32÷75.76 mg kg-1 with 6 over KP value (10 mg kg-1 Cr) and none above the target value of the DL (100 mg kg-1 Cr), Cu with range 2694÷6749 mg kg-1 with 6 samples above the target value of the DL (36 mg kg-1 Cu) and 6 above standard values given in KP value (20 mg kg-1 Cu), Ni with range 59.57÷105.98 mg kg-1 with 6 samples above the target value of the DL (35 mg kg-1 Ni) and 6 above standard values given in KP value (20 mg kg-1 Ni), Pb with range 27.06 ÷96.08 mg kg-1 with 1 sample above the target value of the DL (85 mg kg-1Pb) and 6 above standard values given in KP value (25 mg kg-1Pb), Zn with range 147÷273 mg kg-1 with 6 over target value of the DL (140 mg kg-1 Zn) and 6 above standard KP value (64 mg kg-1 Zn), V with range 34.44÷92.57 mg kg-1 with 5 over target value of the DL (42 mg kg-1 V) and one above KP value (90 mg kg-1 V).In order to compare the level of contamination, the contamination factor (𝐶𝑓 𝑖 ), degree of contamination (Cd), and pollution load index (PLI) were computed. Serious numbers were found for Cu, as, Zn, Co and Ni, which exceeded standard values at almost all samples from both vertical sections. Compared from section 1 and section 2, pollution load index increased by 13.43%, which in almost all samples was classified as heavily polluted to extremely polluted. The fact that mining activities at the Buchim Mine last for almost 40 years, the presence of heavy metals in soils at a serious level is understandable. The high level of contamination is a result of heavy metal persistence and non-biodegradability.