Cadmium and lead contamination and proximate composition of some fresh vegetables

Date

4-2006

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Maxima E. Flavier

Abstract

Fresh vegetables, namely, Momordica charantia Linn. (ampalaya), Colocasia esculenta (gals), Ipomea aquaitca (kangkong), Brassica juncea (mustasa), Brassica chinensis (pechay) and Corchorus olitorius (saluyot), were obtained from a nearby public market outside UPLB campus. The cadmium, lead and iron contents of the vegetables were analyzed using Flame Atomic Absorption Spectrophotometty (FAAS). The samples were prepared by dry ashing and microwave digestion. Proximate composition of the samples were also determined.

Using the dry ashing procedure, the cadmium, lead and iron concentrations were highest in B. juncea, B. chinensis and C. olitorius, respectively and the lowest concentrations were observed in C. olitorius, M. charantia Linn. and B. juncea. Utilizing the microwave digestion procedure, B. chinensis showed the highest cadmium and lead levels. On the other hand, C. olitorius had the highest iron level. It was I. aquatica which had the lowest concentrations for cadmium and lead while M. charantia Linn. showed the lowest iron concentration.

The accuracy of the method was determined by obtaining the percent recovery using samples spiked with known concentrations of the standard solutions. The highest percentage recovery for cadmium obtained from I. aquatica spiked with a middle level cadmium standard and digested using microwave digestion (129.66%). For lead, dry ashing yielded the highest recovery (115.87%) for the vegetable spiked with the middle level lead standard. Microwave digestion gave the highest recovery for iron with the lowest concentration of iron standard (128.55%).

All the species in the study exceeded the maximum allowable lead concentration (4.0 ppm fresh weight) set for vegetables by the Agency for Toxic Substances and Disease Registry (1993). Cadmium concentrations in the samples did not exceed the maximum allowable limit (1.0 ppm fresh weight).

Proximate analyses of the fresh vegetables were done to determine their nutritional value. The highest crude protein and crude fat amounts expressed in percent moisture-free basis were seen in mustasa (24.15 ± 1.20) and gabi (5.19 ± 0.63), respectively.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2006 C4 P34

Document Type

Thesis

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