UPV Digital RepositoryUPV-DRUniversity of the Philippines Visayas
 

Undergraduate Theses

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13

Browse

Filters

2013 - 20144

Settings

Committee Chair: search.filters.chair.Frio, Ma. AngelesDegree: search.filters.degree.Bachelor of Science in Chemistry

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Optimization of pretreatment process of lip gloss for the determination of lead by flame atomic absorption spectroscopy
    Bolivar, Eduardo L., Jr. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2013-10)
    The optimization of the pretreatment process for the analysis of lead in lip gloss using a flame atomic absorption spectrophotometer (FAAS) was proposed in this study. Two variables were tested for this study: volume of nitric acid, HNO3 and volume of hydrogen peroxide, H202. Results of the optimization and statistical analysis revealed that 47.3 mL HNO3 and 2 mL HNO3 were the optimum volumes suited for the digestion of lip gloss in obtaining high analytical results for the lead analysis. Five different samples were randomly purchased from local markets in Iloilo City that may contain high levels of lead due to a report from BFAD that warned people about the use of several lipsticks imported abroad. Lip gloss samples were analyzed using the optimized protocol. The heavy metal content in the lip gloss samples were found to be between 52.0 - 126.3 mg lead/kg of sample. Results show that these were slightly higher than the allowable limits for lead contents in lip gloss set by BFAD and WHO. One-way ANOVA statistics showed that there was a significant difference in the lead contents among the different lip gloss samples.
  • Thumbnail Image
    Item
    DPPH free radical scavenging activity and total phenolic content of Talisay (Terminalia catappa) seeds
    Bohol, Lyan Jean B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2013-04)
    Free radicals, a class of highly reactive molecules derived from the metabolism of oxygen is believed to be involved in many health disorders. It is generated as by-products of biological reactions or from the environment. Antioxidant-based drugs and formulations for the prevention and treatment of complex diseases have attracted a great deal of research interest in natural antioxidants. It is deemed necessary to screen medicinal plants for their antioxidant potential. Terminalia catappa is a widely-distributed tree in the Philippines with promising potentials in pharmacology. Evaluation of the in vitro antioxidant activity of methanolic, dichloromethane, and hexane extracts of Terminalia catappa seeds were carried out using two assays: 1, l-diphenyl-2-pycrylhydrazyl (DPPH) free radical scavenging assay and total phenolic content assay. Results revealed that methanolic extracts showed a significantly higher free radical scavenging activity and a four-fold increase in its activity relative to the standard Butylated Hydroxytoluene (BHT). Furthermore, methanol, DCM and hexane extracts have high total phenolic content. Present results indicate that Terminalia catappa is a potential source of antioxidant and a good candidate for the development of new nutraceuticals for treatment of diseases. Phytochemical screening to determine the group of secondary metabolites present and toxicity evaluation for recommendation as nutritional substitutes and human consumption are recommended.
  • Thumbnail Image
    Item
    Determination of heavy metal (Cu, Cd, and Pb) concentration in musclemeat of fish from different areas in Batan Bay, Aklan
    Bagarinao, Cathrina F. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2014-04)
    Food safety is of utmost importance but it is usually compromised by the presence of pollutants in the environment such as heavy metals. This study was conducted to investigate heavy metals concentrations in fish musclemeat collected from different areas of Batan Bay, Aklan. A total of 22 fish species were analyzed for Cu, Cd and Pb using Flame Atomic Absorbance Spectroscopy. Pb concentration in the musclemeat of fish ranged from 0.0292 ± 0.2070- 2.09 ±1.15 mg/kg wet weight and was found to be highest in Mugil cephalus (flathead grey mullet), while Cd concentration ranged from 0.0075 ± 0.0016-0.157 ± 0.209 mg/kg wet weight with highest value in Megalops cyprinoides (Indo-pacific tarpon), and Cu concentration ranged from 0.0605 ± 0.0667-2.76 ± 0.05 mg/kg wet weight, with highest concentration in Leiognathus equulus (common ponyfish). Among the metals, only Pb concentration in flathead grey mullet exceeded the maximum permissible concentration in food as indicated by the Joint FAO/WHO Codex Alimentarius (1984). Assessment of Noncarcinogenic Hazard Quotient (NHQ) gave NHQ values less than 1, indicating that the risk of developing adverse effects due to fish intake is low.
  • Thumbnail Image
    Item
    Heavy metal concentrations in sediments from Batan Bay and its tributaries
    Andrada, Mary Royce D. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2014-04)
    The concentration of three heavy metals (Cd, Pb, Cu) in sediments from Batan Bay and its tributaries were determined in order to assess the degree of contamination of sediments in the said area. The samples were digested following the Method 3050B of US Environmental Protection Program (EPA, 1996). The heavy metal concentrations were determined using Flame Atomic Absorption Spectrometer (FAAS). Results show that the heavy metal concentrations ranged from n.d. - 2.57 mg/kg dry weight (dw) for Cd; 16.44-143.02 mg/kg dw for Cu; and 3.18-28.53 mg/kg dw for Pb. Sediment sample collected from BTN #10 has the highest Cd concentration while sediment sample collected from BTN 052 which is a rice field in Batan, Aklan registered the highest Pb and Cu concentrations. Three sediment quality guidelines (National Oceanic and Atmospheric Administration, Canadian Sediment Quality Guideline and Hong Kong Sediment Quality Guideline) were employed to assess the metal contamination in sediments. The concentrations of Cd and Pb in all sites did not exceed the maximum permissible limits set by the three guidelines. As for Cu, BTN 052 exceeded the Upper Chemical Exceedance Level set by Hong Kong SQG. Correlation analysis showed that there is a significant correlation (p <0.01) between Pb and Cu indicating possible similar source input. Special attention must be given to BTN 052 since the levels of the studied heavy metals are high in this area. The results can be used as basis for the pollution level of sediments from Batan Bay and its tributaries. Special consideration should be given to BTN 052 since all of the test metals are significantly high in this area. It is also suggested to in identify the primary sources of metal contamination in this area.