Chemical Evaluation of Trace Elements in Bottled Water

Sales of bottled water have been increasing around the globe. This study was carried out to assess the trace elements present in bottled water. For the study of bottled water, a total of 100 samples of different volumes (20 L and 1 L) were selected. The physicochemical assessments were performed as per the methods described in the American Public Health Association, 2005. Average values of pH, electrical conductivity, total dissolved solids, and turbidity were found to be 5.96 ± 0.54, 59.97 ± 58.65, 4.42 ± 3.69, and 0.408 ± 0.19, respectively. Likewise, average values of total hardness (as CaCO3), calcium (as CaCO3), magnesium (as CaCO3), chlorine, iron, copper, cobalt, nickel, fluoride, sodium, and potassium were found to be 14.78 ± 8.43, 3.26 ± 1.55, 11.51 ± 7.92, 7.51 ± 3.21, 0.0032 ± 0.0017, 0.0091 ± 0.0116, 0.2520 ± 0.0127, 0.0080 ± 0.0082, 0.047 ± 0.0139, 12.65 ± 10.90, and 1.41 ± 2.00, respectively; meanwhile residual chlorine, zinc, silver, cadmium, and lead were below detection limit. All the physicochemical characteristics of bottled water were found to be within International Bottled Water Association (IBWA) guidelines. From the physicochemical aspects, the bottled water was found to be within the permissible value set by IBWA. Pearson’s correlation revealed significant association between trace elements. Levene’s test for equity of variances indicated that the majority (iron, copper, cobalt, nickel, fluoride, sodium, and potassium) of trace elements and seasons (monsoon and postmonsoon) demonstrated a statistically significant distribution (at 95% confidence interval). At elevated concentrations, some elements can be harmful to human health and can cause morphological abnormalities, mutagenic effects, reduced growth, and increased morbidity and mortality in humans but it all depends upon a person’s metabolic factors, genetic factors, and ability to excrete trace elements through different routes, etc. Water could have percolated down from the surface to the ground water and as such the difference in concentration of trace elements in monsoon and postmonsoon seasons could be noticeable.

Low Temperature Sealing of Anodized Aluminum Alloy for Enhancing Corrosion Resistance

Sealing as a post treatment of anodized aluminum is required to enhance the corrosion resistance by filling nanopores, which allow the penetration of corrosive media toward the base aluminum. We designed a mixed sealing solution with nickel acetate and ammonium fluoride by modifying traditional nickel fluoride cold sealing. The concentration of mixed sealing solution affected the reaction rate of sealing and corrosion current density of anodized aluminum alloy. The higher concentration of mixed sealing solution improved the sealing rate, which was represented by a decrease of corrosion current density of anodized aluminum alloy. However, a mixed sealing solution with 2/3 concentration of general nickel fluoride sealing solution operated at room temperature showed the lowest corrosion current density compared to traditional methods (e.g., nickel fluoride cold sealing (NFCS) and nickel acetate hot sealing) and other mixed sealing solutions. Moreover, the mixed sealing solution with 2/3 concentration of general NFCS had a lower risk for over sealing, which increases the corrosion current density by excessive dissolution of anodic oxide. Therefore, the mixed sealing solution with optimized conditions designed in this work possibly provides a new method for enhancing the corrosion resistance of anodized aluminum alloys.

The Role of Mineral and Trace Element Supplementation in Exercise and Athletic Performance: A Systematic Review

Minerals and trace elements (MTEs) are micronutrients involved in hundreds of biological processes. Deficiency in MTEs can negatively affect athletic performance. Approximately 50% of athletes have reported consuming some form of micronutrient supplement; however, there is limited data confirming their efficacy for improving performance. The aim of this study was to systematically review the role of MTEs in exercise and athletic performance. Six electronic databases and grey literature sources (MEDLINE; EMBASE; CINAHL and SportDISCUS; Web of Science and clinicaltrials.gov) were searched, in accordance with PRISMA guidelines. Results: 17,433 articles were identified and 130 experiments from 128 studies were included. Retrieved articles included Iron (n = 29), Calcium (n = 11), Magnesium, (n = 22), Phosphate (n = 17), Zinc (n = 9), Sodium (n = 15), Boron (n = 4), Selenium (n = 5), Chromium (n = 12) and multi-mineral articles (n = 5). No relevant articles were identified for Copper, Manganese, Iodine, Nickel, Fluoride or Cobalt. Only Iron and Magnesium included articles of sufficient quality to be assigned as ‘strong’. Currently, there is little evidence to support the use of MTE supplementation to improve physiological markers of athletic performance, with the possible exception of Iron (in particular, biological situations) and Magnesium as these currently have the strongest quality evidence. Regardless, some MTEs may possess the potential to improve athletic performance, but more high quality research is required before support for these MTEs can be given. PROSPERO preregistered (CRD42018090502).

Investigation on Properties of Anodized 7075 Slurry Cast Aluminum after Sealing

This work investigated the effects of sealing agents on properties of 7075 slurry cast substrate anodized in 1M sulfuric acid solution. The sealing agents tested were hot water, potassium dichromate, teflon, and nickel fluoride. It was found that anodized 7075 slurry cast Al oxide film sealed with teflon gave the highest hardness and the best corrosion resistance. It is possible that the porous oxide film was plugged by teflon, reducing porosity more than hot water, potassium dichromate, or nickel fluoride sealing.