Comparison of spectrophotometric and digital photometric methods of determining iron in rice grains and boron in two hot springs in Laguna.

Date

4-2012

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Solivas, Josefina L.

Co-adviser

Del Rosario, Ernesto J.

Committee Member

Rodriguez, Myrna S.

Abstract

The total boron content, mg B/L, of water samples from two selected hot springs in Laguna, Laguna hot spring and Libis ng Nayon, and the % total iron in brown and well-milled rice grains (PSB RC 18) were determined using visible spectrophotometry and digital photometry. The colorimetric methods used were the Curcumin method and Phenanthroline method for boron and iron analysis, respectively. Digital photometry employed a light box, a digital camera, and the software RGB Analysis of Image Colors. Three digital photometric plots, a*, b*, %luminance, obtained from the RGB values of the photographs of the solutions were used to determine the boron and iron concentration of the samples. The light box’s settings were validated for conformity to Beer’s Law using standard solutions of potassium permanganate. Samples containing iron and boron were then analyzed using digital photometry and visible spectrophotometry. T-test showed that the concentrations of boron and iron obtained from both methods were comparable at 95% confidence level. Mean boron levels in the two hot springs were 3.08 ± 0.01 and 2.21 ± 0.02 mg B/L. Mean Fe content in brown rice was 1.14 ± 0.02 % and in polished rice was 0.63 ± 0.04 %, The dynamic range for B was determined at 0 to 5 mg B/L, while for Fe was 0 up to 10 mg Fe/L The accuracy of the digital photometric method was also tested by analyzing known amounts of iron and boron, statistical analysis was done at 95 % confidence level, and results indicate that the method was accurate. Test of repeatability and precision was also done; statistical analysis showed that there was no significant difference between replicate runs at 95% confidence level. Thus, digital photometric analyses using a light box and digital camera were accurate and precise. It may be a practical alternative method for the determination of boron in water samples and iron in rice grains using Curcumin and Phenanthroline methods, respectively.

Language

English

Location

UPLB Main Library Special Collections Section

Call Number

Thesis

Document Type

Thesis

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