Direct Determination of Heavy Metals in Honey by Potentiometric Stripping Analysis

Honey is a valuable nutritious food rich in simple sugars, aminoacids, proteins and minerals. In addition, this food product contains natural phenols and flavonoids, responsible for some bioactive properties. Due to known health benefits of honey and its exquisite flavour this foodstuff is readily consumed by children and wide population imposing necessity of strict quality control. One of quality criteria is the content of heavy metals. Elevated content of heavy metals in honey may result from environmental or processing contamination, or may originate from soil or plant species that honey is derived from.In this work twenty five samples of honey from Serbia, Montenegro and Bosnia and Herzegovina were analysed in respect to zinc, cadmium, lead and copper content. Honey samples were analysed directly, without sample preparation, by applying potentiometric stripping analysis. Zinc, cadmium and lead were quantitated by using indium as an internal standard, whereas copper was determined by standard addition method. Method accuracy was confirmed by blind analysis of standard samples and with good recovery results which, for analysed samples, were in the range 91-101%. In all analysed sampled determined metals contents were in the range permitted by Serbian regulations. Cadmium was not detected in any of the analysed samples, whereas the content of other metals were in the range of 0.01-3.6 mg/g for zinc, 0.02-0.8 mg/g for lead and 0.1-2.4 mg/g for copper, respectively

Electrosynthesized molecularly imprinted polyscopoletin nanofilms for human serum albumin detection

Molecularly imprinted polymers (MIPs) rendered selective solely by the imprinting with protein templates lacking of distinctive properties to facilitate strong target-MIP interaction are likely to exhibit medium to low template binding affinities. While this prohibits the use of such MIPs for applications requiring the assessment of very low template concentrations, their implementation for the quantification of high-abundance proteins seems to have a clear niche in the analytical practice. We investigated this opportunity by developing a polyscopoletin-based MIP nanofilm for the electrochemical determination of elevated human serum albumin (HSA) in urine. As reference for a low abundance protein ferritin-MIPs were also prepared by the same procedure. Under optimal conditions, the imprinted sensors gave a linear response to HSA in the concentration range of 20–100 mg/dm3, and to ferritin in the range of 120–360 mg/dm3. While as expected the obtained limit of detection was not sufficient to determine endogenous ferritin in plasma, the HSA-sensor was successfully employed to analyse urine samples of patients with albuminuria. The results suggest that MIP-based sensors may be applicable for quantifying high abundance proteins in a clinical setting

Trends in thyroid cancer incidence and mortality in Central Serbia, 1999-2014

Introduction. Thyroid cancer (TC) is the the most common malignant disease of the endocrine system. The incidence of the TC has been increasing worldwide, especially in female population. However, mortality from TC is low in both males and females. The objective of the paper was to determine and analyze incidence and mortality trends of TC in males and females in the central Serbia in the period 1999-2014. Method. Descriptive study was used. Data were obtained from the Serbian Cancer Registry. Crude and age-adjusted rates (ASR) of incidence and mortality were calculated. Trend and annual percentage change (APC) of the incidence and mortality rate with corresponding 95% confidence intervals (CI) were calculated by performing Jointpoint regression analyses. Results. A total number of new cases of TC was 3113. TC was diagnosed in 2343 females and 770 males (female-to-male ratio, 3 to 1). A total number of fatal cases was 770 (while 504 female and 266 male died from TC, female-to-male ratio, 2 to 1). TC was not common before 30 years of age. The highest incidence was recorded both in males and females aged 50-59. Joinpoint regression analysis showed the statistically significant increase of ASR of TC incidence in males in 1999-2014 period with APC of 6.2% (95%CI:4.2-8.3, p<0.001) and there was also significant increase of ASR of TC incidence in females in the same study period with APC of 6.1% (95%CI: 4.2-8.0, p<0.001). Joinpoint regression analysis showed an insignificant increase of ASR of TC mortality in males with APC of 2.4% (95%CI:-0.5-5.5, p=0.1). There was an insignificant decrease of ASR of TC mortality in females with APC of -1.3% (95%CI: -4.4-1.9, p=0.4). Conclusion. The increasing trend of age-adjusted incidence rate of TC both in males and females and decreasing trend of age-adjusted mortality rates of TC in during the period were registered. Females had higher age-adjusted incidence and mortality rates than males. Female to male ratio of incidence was 3:1 and for mortality 2:1. Measures of primary and secondary prevention are needed.

Fatty and volatile oils of the gypsywort lycopus europaeus L. and the gaussian-like distribution of its wax alkanes

The detailed analyses of the volatile essential oil and lipid profiles of the aerial parts from the blooming and fruit-forming stages of both ripe and unripe fruit of Lycopus europaeus (Lamiaceae) are presented. Both of these profiles are distinguished by components with a restricted occurrence in the Plant Kingdom. These rare compounds include (E)-hotrienol in the volatiles, numerous unusual fatty acids (such as very long chain, odd-numbered and branched-chain) in the bound lipids and a high amount of iso- and anteiso-alkanes in the epicuticular waxes. Furthermore, a Gaussian-like distribution of the relative amounts of the epicuticular wax alkanes was observed. These normal distributions could be interpreted as the end result of the work of elongase enzyme systems where the Gaussian parameter μ should match the length of the “ideal” fatty acid biosynthesised and σ would represent the error of this enzyme system. These curve parameters were shown to have a close relationship with ACL and CPI values usually utilised to describe the natural distribution of wax alkanes. The screening of L. europaeus essential oil for its in vitro antimicrobial activity showed that this oil possesses selectivity towards two gram-negative strains, E. coli and K. pneumoniae

Molecular characterization of Cronobacter sakazakii isolated from different herbal teas and mixtures in Serbia

Cronobacter sakazakii je uzročnik humanih infekcija koje mogu prouzrokovati ozbiljne i čak fatalne posledice kod odojčadi i imunokompromitovanih odraslih osoba i dece. Zbog visoke tolerancije na osmotski stres, C. sakazakii je često izolovan iz dehidratisanih proizvoda, kao što su formule za bebe u prahu i biljni čajevi. Cilj ovih istraživanja je detekcija, identifikacija i molekularna karakterizacija Cronobacter sakazakii izolata iz formula za bebe i različitih biljnih čajeva uzorkovanih u prodavnicama u Srbiji ili testiranih pri kontroli izvoza. U svih 360 analiziranih uzoraka mleka u prahu za bebe nije detektovana kontaminacija bkterijom C. sakazakii. Medjutim, u 192 od 520 testiranih uzoraka čajeva utvrdjeno je prisustvo C. Sakazakii (37.1%). Visoka zastupljenost je detektovana u čajevima za decu - 51.6% i u “bebi” čajevima - 44.1%, a zatim u čajevima za medicinsku upotrebu -38%. Najveća grupa čajeva koji sadrže 1 biljnu vrstu (221) sadržala je 72 C. sakazakii - pozitivnih uzoraka (32.6%) i uključivala je čajeve od Sennae folium, Althaeae radix, Menthae piperitae folium, Chamomilae flos i Urticae folium. Molekularna karakterizacija izolovanih C. sakazakii iz različitih biljnih čajeva rep-PCR, RAPD i 16S rRNA analizom sekvenci ukazala je na visok stepen sličnosti soju C. sakazakii NCTC 8155. S obzirom da je ovo jedan od najpatogenijih kliničkih sojeva, ovi rezultati ukazuju na potrebu za povećanom kontrolom zbog mogućeg rizika koju ove namirnice predstavljaju za imunokompromitovane i zdrave korisnike, a posebno za bebe i decu.Cronobacter sakazakii is an important cause of human infections that can be serious and even fatal among premature neonates and immunocompromised adults or infants. Because of its high tolerance to osmotic stress, C. sakazakii is frequently isolated from dried foods, such as powdered infant formula and herbal teas. The aim of investigation was detection, identification and molecular characterization of Cronobacter sakazakii isolates from infant formula and various herbal teas collected from Serbian market and tested for import control. C. sakazakii was not detected in any of the 360 analysed samples of powdered infant formula. However, 192 out of 520 samples of herbal teas tested were positive for C. sakazakii (37.1%). The high prevalence was observed in teas for children (51.6%) and in “baby” teas (44.1%), followed by medicinal teas (38%). The largest one-herb-teas group (221 samples) contained 72 C. sakazakii-positive samples (32.6%) and involved Sennae folium, Althaeae radix, Menthae piperitae folium, Chamomilae flos and Urticae folium teas. Molecular characterization of isolated C. sakazakii from different herbal teas by rep-PCR, RAPD and 16S rRNA sequences analysis showed the high similarity to C. sakazakii NCTC 8155. Knowing this strain as one of the most pathogenic clinical strains, our results raise concern about the safety risks these foods pose to immunocompromised and healthy consumers, especially for babies and children