Asma Akhter

Document Type

Thesis

Date of Award

Spring 5-17-2013

School/College

College of Science, Engineering, and Technology (COSET)

Degree Name

MS in Chemistry

First Advisor

Professor Bobby Wilson

Abstract

This research was conducted for the sole purpose ofmeasuring the concentration of some trace metals in some water samples within the greater Houston metropolitan area. These water samples were collected from sources associated with the City of Houston, Texas municipal water systems such as Houston. It is the most populated city in Texas. To achieve this, twenty four water samples were randomly collected to serve as the subjects ofthe study. The samples were collected from tap water sources. The presence of trace metals in drinking water is of concern to our health. Ofthe trace elements studied, uranium is of special concern due to risks of nephrotoxicity and high blood pressure that are associated with U exposure. Typically homeowners are getting drinking water from pipes which bring the water directly from the ground and do not know what is in the water they are drinking. However, this lab technique of using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is providing a means to 1 2 determine whether or not any trace metals are in the drinking water, and, if so, what concentrations are present there. An analytical technique usmg ICP-MS was established to measure the concentration ofmolybdenum (Mo), cadmium (Cd), tin (Sn), uranium (U), and lead (Pb) in drinking water, which is normally sourced from ground water. ICP-MS was used to determine levels of trace metals directly in ground water. Most of the target elements were present in parts-per-trillion (nanogram-per-liter [ng/L]) concentrations. Prior to analysis, the water samples were treated with O.OSM RN03. The results showed that trace metals were significantly low in the Houston area drinking water. Previous data from the City of Houston showed the presence of measurable uranium (U) concentrations in different parts of the city. This news was first made public by Mark Greenblaft of television station KHOU stating "The City ofHouston is one ofthe major cities in Texas with radioactive elements like uranium and radium present in drinking water, according to the data provided by the Texas Commission and Internal City of Houston e-mail (KHOU News by Mark Greenblaft, November 16,2010)." The analytical process used a clean-lab procedure in an ICP-MS method. The samples were then collected from Texas Southern University, Claiborne campus, as well as Harris County, Katy, Sugarland, Stafford, Cypress, Missouri City, South Fry road, and Pearland. A multi-element standard was used in this study. The data showed the following variations of concentrations: for Mo, 100ng/L 203Sng/L, Cd, 3.30ng/L-S.S3ng/L, Sn, 12.63ng/L-41.8ng/L, U, 0.680 ng/L-183ng IL, and Pb, S2.S0ng/L - 2063ng/L. A blank solution was used as a control. 3 It was therefore concluded that proper water analysis procedure was given the concentrations of trace metals (Mo, Cd, Sn, U and Pb) in drinking water (ground water), and it was very low. The limit was 0.680ng/L - 2035ng/L. Cadmium (Cd) had the lowest concentration, and it was 3.30 ng/L- 5.53 ng/L; lead has the highest concentration, and it was 52.50ng/I-2063ng/L.

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