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Influence of halogen interactions on the energetic properties of halogen-substituated polycyclic nitroaromatic molecules
No full textDetrimental effects of cadmium on male infertility: A review
No full textInfertility has become a serious health and socio-economic-psychological problem globally. The harmful role of trace metals in male infertility is recognized but still not sufficiently explained. Herein, a comprehensive review was conducted to elucidate the detrimental role of cadmium (Cd) on male infertility, particularly on infertility with unknown (idiopathic) causes. Peer-reviewed studies from 2000 to 2024 dealing with seminal plasma and blood Cd levels of fertile and infertile men were retrieved were interrogated with regard to strict inclusion/exclusion criteria, and then were thoroughly reviewed and analyzed. Another aim of this review was to indicate the potential effects of Cd on changes in seminogram findings. A median range of seminal plasma Cd levels from 0.2 to 1.5 µg/L can be considered safe for men’s fertility. This review strongly implies that Cd levels were notably higher in seminal plasma of infertile cases than controls. The review’s data also indicate that exposure to tobacco smoke is a major source of elevated seminal and blood Cd levels in infertile men. Newer research points to the importance of Cd in lower levels from the environment on changes in seminogram findings, primarily count, motility of spermatozoa, and their morphology. Overall, this review implies that seminal plasma Cd levels could be a good indicator of semen quality. However, new, in-depth studies are needed to confirm or reject the causal relationship of Cd with male infertility
Ispitivanje uticaja PFOA na fiziološke karakteristike biljaka iz porodice Cucurbitaceae
No full textŠiroka upotreba per- i polifluoralkilnih supstanci (PFAS) izaziva ozbiljnu zabrinutost zbog njihovog negativnog uticaja na životnu sredinu i zdravlje ljudi. Ove hemikalije, koje karakterišu visoka hemijska stabilnost i otpornost na razgradnju, dovode do dugotrajnog zagađenja zemljišta i vodenih ekosistema. Tradicionalne metode remedijacije pokazale su se neefikasnim u uklanjanju PFAS jedinjenja, zbog čega je neophodno razvijati alternativne, održive pristupe.
Zbog toga se ovaj rad fokusira na ispitivanje novih pristupa remedijaciji, tačnije na primenu fitoremedijacije u uklanjanju PFAS kontaminanata iz zemljišta i vode. Poseban akcenat stavljen je na ispitivanje potencijala krastavca (Cucumis sativus) i tikvice (Cucurbita pepo) da tolerišu, preuzimaju i akumuliraju PFOS i PFOA jedinjenja.
Fitoremedijacija se zasniva na sposobnosti biljaka da apsorbuju zagađujuće materije putem korenovog sistema i akumuliraju ih u nadzemnim delovima biljke, čime se postiže njihovo uklanjanje iz životne sredine. Ova tehnologija pokazuje veliki potencijal kao ekološki prihvatljivo, efikasno i ekonomski isplativo rešenje za in situ remedijaciju PFAS kontaminiranih područja, pružajući realnu alternativu konvencionalnim metodama sanacije
Razvoj, validacija i primena metode za određivanje sadržaja oksalne kiseline u medu
No full textCilj ovog završnog rada je definisanje osnovnih parametara koji se procenjuju tokom validacije analitičke metode, kao i opisivanje eksperimentalnih postupaka za njihovo određivanje. Obrađeni su sledeći parametri: selektivnost, linearnost, granica detekcije (LOD) i kvantifikacije (LOQ), radni opseg, preciznost (ponovljivost i unutarlaboratorijska reproduktivnost), tačnost i robusnost. Zatim je prikazano kako se postupak validacije sprovodi u praksi, na primeru prethodno razvijene metode za određivanje oksalne kiseline u medu primenom visokoefikasne anjonskoizmenjivačke hromatografije sa konduktometrijskom detekcijom.
Metoda je pokazala zadovoljavajuću selektivnost (rezolucije između susednih pikova iznosile su 1,81 i 5,80) i visoki stepen linearnosti u opsegu koncentracija od 1 mg/L do 10 mg/L (r = 0,9998). Na osnovu kalibracione prave izračunate su granica detekcije (2,90 mg/kg) i granica kvantifikacije (8,79 mg/kg). Radni opseg metode definisan je u opsegu koncentracija od 0,88 mg/L do 10,79 mg/L. Preciznost metode u skladu je sa Horvicovim modelom (HorRat(r) = 0,39 i HorRat(R) = 0,41), dok je tačnost zadovoljavajuća na sva tri ispitana koncentraciona nivoa (povratni prinos je veći od 92%). Metoda je primenjena i na realne uzorke meda, pri čemu je sadržaj oksalne kiseline u njima bio nizak, odnosno ispod granice kvantifikacije metode
Size and end-group chemistry of linear polyethylene terephthalate oligomers matter in chemical risk assessment
No full textCyclic and linear oligomers, formed as side-products during PET polymerization, are poorly characterized non-intentionally added substances (NIAS) in food. Risk assessment of PET oligomers is challenging due to their size, number, isomerism, complexity in structure, and lack of analytical standards. The great heterogeneity in size and structure of PET oligomers calls for a systematic approach in risk assessment and hazard identification. The aim of our study was to synthesize and characterize physicochemical properties, protein, DNA and cellular interactions of a series of linear methylated and non-methylated PET oligomers (monomer, dimer and trimer). Our results show striking differences in the properties of PET oligomers in relation to size and end-group chemistry (methylated vs. free carboxyl-vs. free hydroxyl-). Solubility in food simulants decreases with increase in methylation and the number of aromatic rings. Linear PET oligomers show little to no toxicity in a wide range of concentrations tested in primary cells and are taken up by human monocyte derived dendritic cells. All linear PET oligomers tested readily interact with food and serum proteins resulting in large protein/plastic oligomer aggregates. Methylated PET trimers bind to salmon sperm DNA, leading to significant destabilization of the DNA. Our results point to the importance of size and end-group of PET oligomers in chemical risk assessment: size and methylation of the oligomer strongly contribute to the observed cellular and molecular effects of tested compounds. Larger methylated PET oligomer binding to DNA prompts further research on the toxicological relevance of the observed interactions
Degradacija propranolola natrijum-hipohloritom
No full textCilj ovog rada bio je da se razvije i optimizuje metoda za degradaciju vodenog rastvora propranolola pomoću natrijum-hipohlorita. Natrijum-hipohlorit je jako oksidaciono sredstvo koje može da bude toksično za vodeni ekosistem. Propranolol, čak i pri niskim koncentracijama može da poremeti fiziološke procese kod vodenih organizama (može da utiče na metabolizam i reprodukciju). Tokom hlorovanja i oksidacije (npr. dezinfekcija natrijum-hipohloritom), propranolol može da formira hlorovane proizvode koji mogu da budu toksičniji ili postojaniji od matičnog jedinjenja. Stoga je potpuna razgradnja propranolola neophodna kako bi se izbeglo sekundarno zagađenje. Parametri koji su se koristili u ovoj metodi uključivali su natrijum-hipohlorit, koji je dobijen iz uređaja OksiHLOROGEN i njegove različite koncentracije (0,5, 1, 1,5 mM), različite pH-vrednosti (4, 5,6, 10) i različite koncentracije propranolola (10, 30, 50 ppm). Efikasnost degradacije je praćena pomoću tečne hromatografije visokih performansi. Takođe, merena je i provodljivost rastvora pre i nakon degradacije pomoću konduktometra, kao i pH pre i nakon degradacije pomoću pH-metra. Na osnovu dobijenih rezultata može da se utvrdi da se ova metoda može koristiti za uspešno uklanjanje propranolola iz vodenih matriksa. Na osnovu rezultata može da se zaključi da najmanji uticaj na efikasnost degradacije ima pH-vrednost, dok koncentracija natrijum-hipohlorita ima najveći uticaj. Rezultati su pokazali da je najbolja efikasnost degradacije propranolola pri pH-vrednosti 4, pri koncentraciji propranolola od 30 ppm i pri 1,5 mM koncentraciji natrijum-hipohlorita i iznosila je 99,96 %, dok pri nativnoj pH-vrednosti i pri koncentraciji propranolola od 50 ppm i pri 0,5 mM koncentraciji natrijum-hipohlorita efikasnost degradacije iznosila je samo 42 %
Copper speciation and total essential trace element levels in Wilson’s disease
No full textWilson’s disease (WD) is a rare genetic disorder characterized by impaired Cu metabolism in the body. This study aimed to compare the total levels of essential trace elements (Cr, Mn, Fe, Co, Cu, Zn, Se, and Mo) in plasma and urine samples of WD-treated patients (cases) and healthy controls, and to conduct Cu speciation in plasma samples. Inductively coupled plasma mass spectrometry (ICP-MS) was used for total element concentration, while high-performance liquid chromatography (HPLC) coupled to ICP-MS (HPLC-ICP-MS) was used to determine the following Cu species: Cu-ceruloplasmin (Cu-Cp), Cu-human serum albumin (Cu-HSA), and Cu-low molecular mass (Cu-LMM). In plasma, cases had significantly lower levels of Cu, but higher levels of Zn and Se than controls. In urine, cases had significantly higher levels of Cu and Zn, while the levels of Se, Co, and Mo were significantly lower than in controls. Therapy with ZnSO4 led to higher plasma Zn and Se levels, and higher urine Zn levels, while chelating agent therapy increased urine Cu levels. Among the three Cu species in both cases and controls, the proportion of Cu-Cp was the most dominant, followed by Cu-HSA and Cu-LMM. Long-term drug therapy led to a decline or loss of Cu-HSA and Cu-LMM fractions, offering opportunities for potential plasma biomarkers of WD. Overall, this study provides new insight into the levels of essential trace elements in the plasma and urine of WD-treated cases, the impact of drug therapy on the alteration of specific trace elements and three major species of Cu, potential new biomarkers, and the implications for careful monitoring of drug therapy in WD patients
Ultrasound-Assisted Extraction Followed by Inductively Coupled Plasma Mass Spectrometry and Multivariate Profiling of Rare Earth Elements in Coffee
No full textA rapid and efficient ultrasound-assisted extraction (UAE) procedure followed by inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of 14 rare earth elements (REEs) (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), along with yttrium (Y) and scandium (Sc), in coffee samples. The method was validated using certified reference material (NIST SRM 1547), recovery tests at four fortification levels, and comparisons with microwave-assisted digestion (MAD). Excellent accuracy and precision were achieved, with recovery rates ranging from 80.1% to 112% and relative standard deviations (RSD%) below 14%. Limits of detection (LODs) ranged from 0.2 ng/kg (Yb) to 0.16 µg/kg (Nd). Total REE concentrations varied between 8.3 µg/kg and 1.1 mg/kg, with the highest individual mean concentrations (µg/kg) observed for Ce (11.7), La (6.0), and Sc (4.7). The lowest individual mean concentrations (µg/kg) were for Ho (0.16), Lu (0.066), and Tm (0.063). Multivariate analysis of REE profiles from 92 coffee samples collected in Serbia revealed clear distinctions between ground roasted and instant coffees, as well as between different surrogate blends. This study indicated that the determination of coffee’s geographical origin was not possible due to the diverse types, blends, and additives. However, differences in REE profiles suggest potential classification based on variety. REEs pose a negligible health risk to coffee consumers, with HI values ranging from 4.7 × 10−8 to 6.3 × 10−6 and TCR ranging from 2.6 × 10−14 to 3.5 × 10−12
Razvoj elektrohemijskog senzora na bazi štampane ugljenične elektrode modifikovane kompozitom FeO₂/g-C₃N₄ za osjetljivu detekciju metola u uzorcima riječne vode
No full textVoda je ključna za sve žive organizme i očuvanje ekosistema, ali zagađenje površinskih i podzemnih voda organskim kontaminantima predstavlja ozbiljan globalni problem. Metol (MTL), široko korišćen kao razvijač u crno-bijeloj fotografiji, spada među aromatične amine i fenole koji su prioritetni zagađivači zbog svoje toksičnosti, mutagenosti i kancerogenosti.
Tradicionalne metode detekcije MTL-a, poput hromatografije, su skupe, dugotrajne i zahtijevaju složenu instrumentaciju, dok elektrohemijske tehnike nude osjetljiv, selektivan i ekonomičan pristup. U ovom radu razvijen je elektrohemijski senzor zasnovan na štampanoj ugljeničnoj (SPCE) elektrodi modifikovanoj FeO2 dopovanim g-C₃N4 nanočesticama za selektivno i pouzdano određivanje metola u riječnoj vodi, nudeći ekološki prihvatljivo i primjenljivo rešenje za monitoring životne sredine. Sinteza navedenih nanočestica potvrđena je metodom rendgenske difrakcije (XRD). U cilju razvoja nove metode za detekciju metola, ispitane su elektrokatalitičke osobine FeO2/GCN modifikovane SPCE elektrode. Elektrohemijsko ponašanje MTL-a na novom senzoru ispitivano je cikličnom voltametrijom (CV) kao i diferencijalno pulsnom voltametrijom (DPV). Senzor je pokazao zadovoljavajuće rezultate, sa limitom detekcije (LOD) od 0,52 μM, i limitom kvantifikacije (LOQ) od 1,71. Visoka selektivnost metode potvrđena je analizom potencijalno interferirajućih supstanci. SPCE/FeO2/GCN senzor je pokazao veoma dobre vrijednosti „recovery“-ja, pri detekciji MTL-a u realnim uzorcima riječne vode