Document Type
Thesis
Date of Award
5-31-1989
Degree Name
Master of Science in Environmental Science - (M.S.)
Department
Chemical Engineering, Chemistry and Environmental Science
First Advisor
R. P. T. Tomkins
Second Advisor
Richard B. Trattner
Third Advisor
Barbara B. Kebbekus
Abstract
Toxic metals are present in foods to greater or lesser extention as contaminants, as a result of increasing industrialization, and associated pollution of the biosphere. Lead and cadmium are well known toxic metals which accumulate into the body causing harmful effects at low concentration levels especially in children. Zinc, on the other hand, is an essential micronutrient, but larger levels in foods can be considered toxic.
Twenty eight brands of vegetables including canned, glass packed, frozen and fresh vegetables were analyzed for Pb, Cd, and Zn, in tomatoes, carrots, mushrooms and asparagus. The technique used was Differential Pulse Polarography (DPP) and Atomic Absorption Spectrometry (AAS) as a cross-check method. Five samples and a blank were analyzed for each brand. Two methods were tested to determine the most reliable technique. A dry ashing method using K2SO4/HNO3 proved to be the superior method. The lead concentration found in the analyzed brands ranged from 0.00085 to 0.0429 μg/l0g in carrots; 0.0005 to 0.018 μg/10g in tomatoes; 0.0024 to 0.026 jig/10g in asparagus; and 0.0039 to 0.04 μg/10g in mushrooms.
The cadmium concentration ranged from 0.0038 to 0.144 μg/10g in carrots; 0.0037 to 0.024 jig/10g in tomatoes; 0.082 to 0.076 μg/10g in asparagus; and 0.03 to 0.073 μg/10g in mushrooms.
The zinc concentration ranged from 1.0 to 190.0 μg/10g for carrots; 11.0 to 273.5 μg/10g in tomatoes; 41.18 to 1590.0 μg/10g in asparagus; and 67.76 to 726.4 μg/10g in mushrooms.
The trace concentration of Pb, and Cd, found in the vegetables analyzed does not exceed the maximum allowable level set by FDA. However, Zn gave high concentrations especially in asparagus and mushrooms. Despite the fact that Zn is considered an essential element, this high, concentration can be accumulative and cause adverse health effects.
Recommended Citation
Franca-Romitti, Elizabeth, "Determination of trace amounts of lead, cadium and zinc in vegetables using differential pulse polarography" (1989). Theses. 2753.
https://digitalcommons.njit.edu/theses/2753
