Methods for determination of so2 and reducing sugars in wines and alcoholic beverages

In this study, volumetric methods for determination of SO2 (free and total) and reducing sugars in wines and alcoholic beverages were optimized and validated. The linearity, accuracy and precision of the methods were confirmed using standard solutions of SO2 and reducing sugars (fructose and glucose) prepared in appropriate concentration range, as well as with low, medium and high concentrations. Additionally, the accuracy of the methods was checked by standard additions. Repeatability and reproducibility of the methods was confirmed with repeated analyses of real samples, wines and alcoholic beverages. Obtained results for both methods presented satisfactory accuracy and precision, suggesting that these methods are appropriate for analysis of wines and alcoholic beverage

Method for determination of 35 elements content in various samples with application of microwave digestion and inductively coupled plasma with mass spectrometry (ICP-MS)

Inductively coupled plasma with mass spectrometry (ICP-MS) and microwave digestion system were used as working techniques for determining the content of 35 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Se, Sn, Sr, Ti, V and Zn) in varios samples: edible oils, fruits, vegetables and alcoholic beverages. This paper includes optimization and validation of the conditions for  measurement of the elements isotopes in prepared samples. Method validation was done using calculation of the limit of detection and quantification, lineary, measurement range and measurement uncertainty, as well as the accuracy and precision of the measurements. The examined parameters indicated that the method meets the requirements for the intended use

Isotopic lead measurements in wine and edible oil using inductively coupled plasma with mass spectrometry

Lead isotope ratios provide analytical information related to the source of lead contamination in naturally occurring samples. On the other hand, these measurements can provide useful information for routine means of “fingerprinting” the components grown in different habitats. Studies of the isotopic composition of lead are therefore commonly used in the environmental science as well as geological and anthropological studies. Among all the naturally occurring lead isotopes, only 204Pb is non-radiogenic, whereas, 206Pb, 207Pb and 208Pb are the daughter products from the radioactive decay of  238U, 235U and 232Th, respectively. As a consequence, small Pb isotope abundance variation occurs in nature and the isotopic composition of lead in the environment is dependent on the local pollution sources. Being able to accurately measure all of the Pb isotopes is important for a number of investigations. In this study, inductively coupled plasma with mass spectrometry (ICP-MS) was used to investigate whether this chemical application can offer a reliable and practical solution to the problem of the polyatomic overlap in the presence of organic based matrix samples. The study summarizes the instrument optimization procedure for Pb isotope measurements in wine and edible oil samples. Also, the isotopic ratios were presented for samples from same and from different geographical region

Determination of SO2 and reducing sugars in Macedonian wines

SO2 acts as an effective antoxidant, preventing the activity of the oxidases and antimicrobial agent, showing a potential for bleaching the pigments and elimination of unpleasant odour in wines. Glucose and fructose are the main carbohydrates in grapes and wine, usually called reducing sugars. In this study, three titrimetric methods for determination of SO2 (free and total) and reducing sugars in wines were checked. The linearity, accuracy and precision of the methods were confirmed using standard solution of SO2 and reducing sugars (fructose and glucose) prepared in appropriate concentration range, as well as with low, medium and high concentrations. Additionally, the accuracy of the methods was confirmed by standard additions. Repeatability and reproducibility were confirmed with titration of real samples, analyzed with appropriate repetitions. Validated methods were applied for determination of the content of free and total SO2, as well as reducing sugars in ten Vranec wines produced with different yeasts for fermentation

CHEMICAL COMPOSITION OF RED VRANEC WINES FROM DIFFERENT LOCATIONS

In this study, red Vranec wines (vintage 2014) were produced from grapes grown at different locations: Barovo, Disan, Gradsko and Bitola. Wines were produced with same technology, applying traditional way of production. In addition, following chemical parameters which influence the wine quality were determined: total acidity, pH, volatile acidity, alcohol, SO2 (free and total) and reducing sugars. Wines contained total acids in range from 4.9 to 7.1 g/L and the volatile acidity was in range from 0.4 to 0.52 g/L. The alcohol content was between 8.78 to 14.3 %. All wines were well protected from oxidation containing enough content of SO2. Concerning the reducing sugars concentration, alcoholic fermentation was finished in the wines from Barovo and Disan, while wines from Grasko and Bitola contained small amount of reducing sugars (4,5 g/L). It was concluded that the produced wines presented similar chemical composition and all parameters were in the range of allowed values. Locality did not influence the wine quality. Higher influence on the wine quality has the technology of winemaking.&nbsp

Инструментални фармацевтски анализи (учебник)

Квалитативната и квантитативната анализа на активните компоненти и/или онечистувањата во дадени фармацевтски формулации е од примарна важност во фармацевтската индустрија. Инструменталните методи за анализа во фармацијата се неопходен сегмент, почнувајќи од синтезата па сè до финалната контрола на квалитетот на лековите. Притоа, во зависност од карактеристиките на определуваните компоненти во дадени лекови, најчесто е потребно да се применат повеќе инструментални техники со цел да се добијат веродостојни резултати за присутноста на даден аналит, но и за неговата содржина. Во рамките на овој учебник, наменет за студентите на студиската програма Фармација, претставени се теоретските основи и главните карактеристики на инструменталните техники што најчесто се применуваат во карактеризацијата на фармацевтски формулации. Покрај тоа, дадени се и конкретни примери за апликација на обработените инструментални техники, како и практични примери каде што овие техники може да се употребат во фармацијата. Дадени се и предностите и недостатоците на секоја една техника, а претставени се и практични искуства за ракувањето со некои од инструменталните техники за анализа. Учебникот „Инструментални фармацевтски анализи“ е напишан во форма на практичен прирачник што е неопходен при анализата на фармацевтските формулации. Покрај студентите од студиската програма Фармација, овој учебник може да најде практична примена и во наставата на студиските програми каде што се применуваат инструменталните техники за анализа, на сите циклуси на студирање

Targeted analysis of bioactive phenolic compounds and antioxidant activity of Macedonian red wines

Phenolic composition of twenty-two Macedonian red wines, including ten autochthonous monovarietal Vranec wines produced with different yeasts for fermentation, and twelve wines from international varieties (Syrah, Merlot and Cabernet Sauvignon) from different wine regions was studied. All wines presented relatively high value of total phenols and antioxidant activity. A total of 19 phenolic compounds were identified and quantified using HPLC-DAD and among them, malvidin-3-glucoside and its derivatives were the major compounds, followed by the petunidin derivatives, while caftaric acid was the predominant cinnamic acid derivative in all wines. The anthocyanin content was mainly affected by the grape variety and to a less extent by the yeast used in fermentation. In particular, the use of locally isolated yeasts affected higher amount of anthocyanins and phenolic acids compared to the wines fermented with commercial yeasts. Principal Component Analysis showed a satisfactory grouping of red wines according to the grape variety