Evaluation of Pesticide Residues in Mango by a Multi-residue Analysis and GC/MS Triple Quadrupole

Mango fruit has a great national and international market, and Brazilian production is 1,900 thousand tons/year exporting to North America and Europe. However, the loss could occur during the production when it is affected by pests and climate conditions, so the increased use of chemical substances and their presence should be monitored. A task for governmental agencies, producers and food sales, attending the sanitary barriers requirements, is to distribute food free from contaminants, so laboratories involved in this type of work usually employ multi-residues analysis. The objective of this study was to evaluate the presence of pesticide residues in mango using QuEChERS method and mass spectrometry technique. Positive samples were compared with Brazilian maximum residues level （MRL） and the health risk exposure was evaluated using the acute dietary intake （ADI） parameter. A total of 20 samples were collected from January to March, in Sao Paulo city markets. The recoveries were in the range of 70% to 120%, and standard deviation was below 20%. The category of pesticides not permitted for the crop were found in l0 samples; eight samples presented pesticides below MRL and two samples above MRL for the fungicide procloraz. The ADI values were below 20% of ADI for an adult and the worst case was dimethoate with 69% of ADI for children. The time spent in monitoring studies and the viability of method chosen must be considered by pesticide residues laboratories during routine analysis of food quality control.

Chemical Composition and Antibacterial Activity of Artemisia herba-alba and Mentha pulegium Essential Oils

The chemical composition of essential oils obtained from Artemisia herba-alba and Mentha pulegium were determined. The essential oils were analyzed by gas chromatography coupled with mass spectrometry （GC/MS）. Their antibacterial activity was studied in vitro against three standard strains： E. coli ATCC 25922, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, and five clinical strains： Enterobacter cloacae, Staphylococcus aureus, Pseudomonas pyocyanique, Enterococcus faecium, and E. coli. Nineteen constituents were identified in A. herba-alba essential oil representing 99.57% of the total composition The major component was α-thujone （59.07%）. The bacterial strains were inhibited at concentrations ranging from 1.25 μL/mL to 5μL/mL and killed at concentrations ranging from 1.25 μL/mL to 10 μL/mL. M. pulegium resulted in the identification of eighteen constituents representing 99.48% of the total composition. The main component was pulegone （78.07%）. The minimal inhibitory （MIC） and bactericidal （MBC） concentrations were ranging from 1.25 μL/mL to 2.5 μL/mL.

Statistical modeling of radiolytic (6OCo γ) degradation of Ofloxacin, antibiotic: Synergetic effect, kinetic studies & assessment of its degraded metabolites

The impact of human activities in the past few decades has paved the way for the release of pollutants due to the improper effluent treatment. Recent studies revealed that, Ofloxacin, an antibiotic as one of the major pollutant affecting surface water and ground water. In this study, the radiolytic potential of Ofloxacin was investigated. The effects of pH, dose and concentration of Ofloxacin were analyzed using One Factor At a Time (OFAT) and the interactive effects between the parameters were studied using Face Centered Central Composite Design. The statistically optimised developed model shows 30% degradation at initial antibiotic concentration of ImM at pH 3.0 and at 2 kGy dose of gamma ray. The process efficiency was evaluated in terms of G value and its correlation with the concentration of antibiotic was also established. The process of degradation was augmented by the addition of H2O2 (1.5 mM). The reaction kinetics for the process was evaluated, the dose rate constant and the rate of degradation for the augmented process was found to be 0.232 kGy^-1 and 0.232 mM/kGy, respectively. The degraded metabolites of the radiolytic degradation of Ofloxacin were analyzed through change in pH, reduction in TOC and GC-MS spectrum.

Chemical composition and antimicrobial activity of the essential oil of Cacalia tangutica (Maxim.) Hand.-Mazz

Essential oil of the subterranean part of Cacalia tangutica(Maxim.)Hand.-Mazz was analyzed by gas chromatography(GC)-mass spectrum(MS)technique in two different capillary columns of different polarities.Thirty-one components were identified in the oil and the main compounds were a-zingiberene(13.49%),germacrene D(10.76%),α-pinene(8.54%),caryophyllene(Z-)(6.36%),linalool(6.16%),β-myrcene(4.89%),β-ocimene(Z-)(4.40%)and ocimenone(Z-)(3.58%).The antimicrobial activity of the oil was evaluated against 2 fungi and 12 bacteria including 6 clinically isolated strains using the agar disc diffusion and broth microdilution methods.The results show that the oil presented a broad antimicrobial spectrum and had better antimicrobial activity against yeast and gram-positive bacteria.The minimum inhibitory concentration values were 0.16–5.00 g/L and minimum bactericidal concentration values were 0.16–5.00 g/L.