Spectroscopic Evaluation of Nitrate and Nitrite Concentrations in Selected Fruits and Vegetables

— This study evaluates the concentration of nitrate and nitrite in selected fruits and vegetables sold in Lafia, Nasarawa state. A total of 15 samples comprising two different fruits (orange and watermelon) and three vegetables (spinach, onion and pepper) were used for this purpose. Nitrate content was obtained by derivative spectrophotometric method and nitrite by colorimetric method. The results showed that all fruits and vegetables analyzed contained detectable levels of nitrate and nitrite except for the orange and watermelon purchased from seller B which had nitrate and nitrite content below the detection limit respectively. The mean nitrate concentrations of the samples were 1348.91 mg/kg for orange, 3539.98 mg/kg for watermelon, 3540.00 mg/kg for spinach, 1434.55 mg/kg for onion and 2669.27 mg/kg for pepper. In addition, the mean nitrate concentrations of watermelon, spinach and pepper were above the maximum level of 2500 mg/kg stipulated by EC, WHO and FAO as opposed to those of orange and onion which were below the specified maximum level. Mean nitrite concentrations which ranged from 0.00025 mg/kg to 0.00039 mg/kg for the fruits and 0.00037 mg/Kg to 0.00056 mg/kg for the vegetables were all below the 100 mg/kg maximum level specified by WHO