DETERMINING AND EVALUATING MAGANESE AND ZINC CONTENT IN OYSTERS Crassostrea rivularis (Gould, 1861) IN GIANH RIVER, BA DON TOWN, QUANG BINH

Abstract

Bivalve mollusks (oysters, scallops, mussels, clams, cockle,…) play an important role in cleaning the environment; they are rich in nutritional value and in demand at home and abroad; many of them have become economically valuable commodities. Oysters form the species group of mollusks most exploited in Vietnam. The atomic absorption spectrophotometric method (AAS) has been applied to determine the maganese and zinc content in oysters in Gianh River, Ba Don Town, Quang Binh province. This method has high repetitiveness with RSD <5,06% and recovery from 93,8 % to 103,5% as well as a low limit of detection. The result shows that the average maganese and zinc content in oysters is relatively high (2,03 ÷ 3,01mg/g fresh and 127,82 ÷ 284,95mg/g fresh respectively), the level of safety is within the allowed limits according to the regulation No. 46/BYT 2007. The maganese and zinc content in oysters meets the allowed standards of Vietnam.