Sulfaquinoxaline oxidation by UV-C activated sodium persulfate: Degradation kinetics and toxicological evaluation

This study evaluates the efficiency of sulfate radicals used in advanced oxidation process in water treatment. The targeted pollutant is an antibiotic, sulfaquinoxaline (SQ-Na) sodium, widely used in the veterinary field. The results show a degradation of SQ-Na until 90% after 300 min of irradiation at optimal sodium persulfate (SPS) concentration (200 mg/L). Degradation of the antibiotic obeys a pseudo-first-order kinetics when the concentration of sulfate radicals ranging from 0 to 240 mg/L. The decomposition of SQ-Na via the UV/SPS method is favored significantly under acidic conditions but becomes slow at neutral pH and almost inhibited under alkaline conditions. The contribution of the sulfate radicals alone and of both radicals hydroxyl and sulfate on the SQ-Na degradation is evaluated at 69% and 80%, respectively. Toxicity tests with Sinapis alba and Daphnia magna on treated samples, before and after irradiation, indicate the formation of new by-products more toxic during the treatment process. PRACTITIONER POINTS: SQ-Na was significantly degraded (90%) under UV/SPS system. SQ-Na decay exhibited a pseudo-first-order kinetics. SQ-Na was completely degraded via UV/SPS process under acidic conditions. The shoot growth appears to be more sensitive to oxidation by-products toxicity than root growth. Ineffectiveness in eliminating the ecotoxicity.

Volatile and Sensory Profiles of Algerian Extra-Virgin Olive Oil from Souidi and Zeletni Cultivars

In this study, the volatile and sensory profiles of monovarietal extra-virgin olive oil (EVOO) from two less widespread Algerian autochthonous cultivars (Souidi and Zeletni) were obtained using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry and a panel test, respectively. A total of 14 and 10 volatile compounds belonging to different chemical classes were identified and quantified in the Souidi and Zeletni EVOOs, respectively. Zeletni EVOO contains 2.07 times more (E)-2-hexenal than Souidi EVOO. In addition, the amounts of C6 compounds from LA and LnA, as well as the total amount of the compounds of the LOX pathway were higher in Zeletni than in the Souidi EVOO. Another important finding was the predominance of sesquiterpene β-ocimene in the composition of the volatile fraction of Souidi EVOO. The sensory profiles of the EVOOs analyzed were characterized by fruity, bitter and pungent sensory positive attributes, perceived at medium intensity in both oils studied.

Physicochemical characterization and determination of chloramphenicol residues and heavy metals in Algerian honeys

The concentration of certain heavy metals in various foods (fruits, cereals, legumes, and bee products) produced in industrial and urban cities is increasing each year following industrial development. Quality of honey and its contamination by different polluting agents are related essentially to its production environment, or it can arise from beekeeping practices. In the present study, the determination of physicochemical properties: moisture, pH, total acidity, electric conductivity, hydroxymethylfurfural (HMF), sugars, and chloramphenicol (CAP) residues; the metal content by determination of two toxic metals levels: lead (Pb) and cadmium (Cd); and other trace elements: magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and nickel (Ni) in 23 different honey samples collected from North regions of Algeria were investigated. The physicochemical properties and the metal contents were found within the ranges established by the international standards. For the antibiotic residues, only four honey samples are contaminated by CAP. Metals were found in non-significant values and are in safety baseline levels for human consumption except Mg which exceed the limits. These results suggested that honey could be used as an indicator to detect contaminating agents from the environment since bees are excellent sentinels for assessing environmental contamination because of their physiological and biological characteristics.