In this paper the object of study was to determine the chemical nature of foxing stains in paper. Purpose of the study: Was to deepen the knowledge on the paper with special emphasis on foxing stains, their chemical nature and morphological aspects of foxing stains. Methods used: Are photography under different illuminations and optical microscopy. The presence of fibers disruption was observed with (SEM-EDS), it was used also (ATR-FTIR). Micro X-ray diffraction was used to evaluate the crystalline fillers in the sample. Mass Spectrometry was used for chemical analysis to identify the organic components. Conclusion: Unfoxed and foxed areas of paper samples showed no differences from a morphological point of view. The sample' surface was structurally organized, paper fibers seem to be in good condition, without any visible disturbance. The combination of several non-destructive techniques allowed the characterization of paper composition and the evaluation of morphological aspects.

Caffeine is naturally present in tea and coffee giving the pleasant and stimulant effect. Several different types of teas, black, green, and white teas bought in market were analysis for caffeine content. The boiled sample tea was filtered through filter paper. Lead(II) acetate was used to separate tannins from caffeine followed by filtration through filter paper with a black ribbon. The liquid-liquid extraction was carried out using dichloromethane (3×5 mL) and sodium sulfate as a drying agent. The TLC method was performed on Merck precoated silica gel plates 5×10 cm (60F254, 200 μm) using either methanol or dichloromethane as solvents and the mobile phases were glacial acetic acid and ethyl acetate (95:5, v/v), while the second one was consisted of ethyl acetate and ethanol (80:20, v/v), respectfully. The Rf values were 0.36 and 0.86 for the first and the second mobile phase, respectively, in comparison to the standard caffeine. The values for pH of boiled sample teas were in the range from 4.85 to 5.80. The most abundant tea sample for caffeine was determined in green tea bought in the grocery store for health nutrition (2.04 %). The yield for tea samples from green market, white tea and two tea black samples were 0.06, 0.71, 0.07, and 0.05%, respectively. The developed TLC method can be used for determination of caffeine content in tea samples.

In this study, five samples of honey (4 from various beekeepers and 1 from a local supermarket) were analyzed to determine the presence of Pb, Fe, Mn, Al, Cu, Cr, Zn, Cd, As, Ni and Se content using atomic absorption spectrometry. Samples were collected from the following locations: 2 from Skopje, 2 from Kumanovo and 1 from Preshevo, Srbia. HPLC was applied to determine sugars in honey samples. Acid and moisture were also determined. The average values of concentration were from 0.033 to 0.055 mg/kg, 0.610to 2.498 mg/kg, 0.052 to 0.377 mg/kg, 2.133 to 3.474 mg/kg, 0.060 to 1.034 mg/kg, 0.005to 0.019 mg/kg, and 0.067 to 0.085 mg/kg for Pb, Fe, Mn, Al, Cu, Cr, and Zn, respectively. Cadmium was determined in one sample (0.040 mg/kg), while the presence of arsenic, nickel and selenium were not observed. The total amount of reductive sugars was within the standard value of min 60 g/100 g honey. The moisture was from 16.6 to 17.6% (max 20%). The acid content was recorded from 9 to 28mEq/1 kg honey (max 50mEq/1 kg honey). The results were compared with the safety standards established from the Ministry of Agriculture, Forestry and Water Economy. In general, the analyzed parameters are within the standards and honey can serve as good dietary source.