Comparative Study on Determination of Percentage Purity and Essential Elements on Rock Salt Samples of Different Origins

Abstract

Black and white rock salts are one of the highly used ingredients in daily meal and different types of food industries. Black rock salt is called as bire noon and white rock salt is called as sinde noon in Nepali. These rock salts are being highly used in herbal formulations too. Rock salts of Indian and Tibetan origins are primarily found in Nepalese market. Salt of Nepalese origin, available from Mustang district, is also sold in market. Majority of these salt samples are found to be sold in unprocessed form. Hence, it is likely that these samples may have different level of toxic impurities. Salt containing high amount of essential elements is considered to be of high nutritional value. Therefore, information on level of toxic impurities and essential elements in the salt samples is an important task to know nutritional value of any salt. However, such information on salts of Nepalese market is not available in literature. The amount of sodium in the black salt sample determined potentiometrically was found to be in the range of 30-37mg/100mg of salt sample. In white salt samples, relatively lower amount of sodium in the range of 23-35mg/100g was obtained. Iron was detected in all the collected white and black rock salt samples. The amount of iron in the black and white salt samples was found to be in the range 12-24 and 7-14 ppm, respectively. This tells that black salt is better source of iron than white salt. The low level of magnesium was found two black salt samples only, whereas it was detected in nine white salt samples in the range of 0.1-5 ppm. On the other hand calcium in not detected in all the white and black salt samples. The preliminary AAS measurement in few selected samples showed that Hg and As beyond the WHO safe limit. This study showed that white and black salt is a good source of sodium and iron.