Application of Dispersive Liquid-Liquid Microextraction in Separation and Preconcentration of Silver prior its Determination by Flame Atomic Absorption Spectrometry

A simple, sensitive, and rapid dispersive liquid-liquid microextraction (DLLME) method is developed for the preconcentration of silver ions prior to determination by flame atomic absorption spectrometry (FAAS). In this work, 1-phenyl-1,2-propanedione-2-oximethiosemicarbazone (PPDOT), chloroform, and methanol are used as the complexing agent, extraction solvent, and disperser solvent, respectively. The effects of different analytical parameters on the complex formation and the extrac-tion efficiency are investigated and optimized. The effects of interfering ions on the determination of silver(I) are also examined. Under the optimized conditions, a linear calibration curve was achieved in the range of 0.60−120.0 µg L−1, with the detection limit of 0.61 µg L−1. The pre-concentration factor calculated as the ratio of the slopes of the calibration graphs with and without the pre-concentration was 35.5. The relative standard deviations (RSDs) for the silver(I) determinations were below 3 %. The proposed separation procedure was successfully applied to the determination of silver(I) in natural water and photographic film samples with satisfactory results (recoveries > 95 %)

Effects of Dietary Zinc Oxide and a Blend of Organic Acids on Broiler Live Performance, Carcass Traits, and Serum Parameters

ABSTRACT This experiment was carried out to evaluate the effect of different dietary supplementation levels of zinc oxide and of an organic acid blend on broiler performance, carcass traits, and serum parameters. A total of 2400 one-day-old male Ross 308 broiler chicks, with average initial body weight 44.21±0.19g, was distributed according to a completely randomized design in a 2 x 3 factorial arrangement. Six treatments, consisting of diets containing two zinc oxide levels (0 and 0.01% of the diet) and three organic acid blend levels (0, 0.15, and 0.30%) were applied, with eight replicates of 50 birds each. The experimental diets were supplied ad libitum for 42 days. There were significant performance differences among birds fed the different zinc oxide and organic acid blend levels until 42 d of age (p<0.01). The result of this experiment showed that the organic acid blend did not affect feed intake, but zinc oxide increased feed intake. Carcass traits were not influenced by the experimental supplements. Zinc oxide supplementation increased serum alkaline phosphatase level (p<0.01). The organic acid blend reduced serum cholesterol and triglyceride levels (p<0.05). No interactions were found between zinc oxide and the organic acid blend for none of the evaluated parameters. We concluded that zinc oxide and the evaluated organic acid blend improve broiler performance

Draft Genome Sequence of Nesterenkonia sp. Strain F, Isolated From Aran-Bidgol Salt Lake in Iran

The draft genome of the aerobic, Gram-positive, halophilic chemoorganotroph Nesterenkonia sp. strain F consists of a 2,812,133-bp chromosome. This study is the first to report the shotgun-sequenced draft genome of a member of the genus Nesterenkonia