Section II: Chemistry (Briefs‪)‬

CORRELATIONS BETWEEN CALCIUM, MAGNESIUM AND HARDNESS OF WATER IN THE DRINKING WATERS OF DECATUR COUNTY GEORGIA AND THE INCIDENCE OF CARDIOVASCULAR AND CEREBROVASCULAR DISEASES, Abe A. Ojo (1) and Manju Sharma, (1) Atlanta Metropolitan College, Division of Science and Mathematics, 1630 Metropolitan Parkway, SW, Atlanta, GA 30310. Many epidemiological studies have found some association between the levels of calcium, magnesium, hardness of water, and mortality rate from cardiovascular disease (CVD) in general and in its component cerebrovascular disease (CBVD). Several studies have established that there is inverse correlation between presence of calcium and magnesium in drinking water and CVD, as well as CBVD. In the current study, we are presenting the link between water hardness, calcium and magnesium levels, CVD and CBVD in Decatur County of Georgia, USA. The drinking water samples from different regions and sources were analyzed by using the ethylenediaaminetetraacetic acid (EDTA) titrimetric procedure. In the study we found that the surface water sources (lakes, ponds and river water) contained low concentrations of water hardness ranging from 3.66mg/1 to 33.05mg/L) and its calcium and magnesium ranged between 3.15-30.15mg/L and 0.38-2.90mg/L respectively. The municipal drinking waters were determined to vary in concentrations from between 41.00 mg/L to 47.31mg/L, hardness; 37.23mg/L to 44.25 mg/L, Calcium; and 3.06 mg/L to 4.45mg/L, Magnesium. The drinking waters obtained outside the municipal city limits are mainly from boreholes (well ground waters) which were determined to show geographic variations ranging from between 43.69mg/L to 68.06mg/L for hardness of water; and for calcium and magnesium ranged from between 37.40 mg/L to 58.05mg/L and 2.00mg/L to 21.77mg/L, respectively. Commercially available bottled waters obtained in Bainbridge city exhibited wide variations in concentration levels amongst different brands which were found to collectively ranged from between 1.62 mg/L to 158.08 mg/L for Calcium, 0.99 mg/L-13.99 mg/L for Magnesium and 2.61 mg/L to 169.13 mg/L for the hardness of water. Other than certain commercial drinking waters, only the drinking water sources outside the municipal city limits appears to have higher levels of hardness, calcium, and magnesium. We have determined that the mortality rate caused by CVD is lower outside the municipal city limits compared to within the Bainbridge city limit. We found an inverse correlation to the low CBVD mortality rate due to CBVD in Decatur County. The ratio of high calcium and low magnesium is responsible for the inverse correlation to the low CBVD mortality rate. We found that there was a positive correlation between the levels of magnesium and CBVD. The bottled water samples show variation in concentrations of calcium and magnesium, and no correlation with brands can be made in this regard to CVD and CBVD. This study is raising question concerning the involvement of magnesium levels in drinking water with CBVD and its supposed beneficial effects against CVD. Further research will be needed to answer this question. ANALYTICAL APPLICATIONS OF COULOMETRIC TITRATION IN UNDER-GRADUATE LABORATORY **, Rajeev B. Dabke, Department of Chemistry and Geology, Columbus State University, Columbus, GA 31907. We recently embarked on a program aimed at developing experiments for a new undergraduate laboratory course in electroanalytical chemistry. Coulometric titration methods have been applied to analyzing active ingredients of household products. Known current was passed to electrochemically generate a suitable reagent. Faraday MP potentiostat was used to generate constant current. In situ generated reagent reacted with the specific ingredient present in a sample. Stoicheometric endpoint of the reaction was detected by potentiometric sensor electrodes or by visual color change caused by an indicator. The charge required to generate reagent precursor to reach the end poi