The development of a rapid sensor for Biochemical Oxygen Demand (BOD) is important for rapid determination of the degree of pollution in river water. A short–term BOD (BODst) has been developed using a consortium of locally isolated bacteria as the sensing element. YSI 52 Dissolved Oxygen Meter has been used to measure the oxygen uptake in the test solutions. Of the three alginate–based matrices, namely calcium alginate, calcium alginate–gluteraldehyde and polyvinyl alcohol–sodium alginate (PVA-SA), calcium alginate–gluteraldehyde was found to be the best microbial immobilization method. Typical response time of the developed BODst sensor was 8 minutes, and the immobilized microorganisms were suitable for single use. BOD response was observed at 37°C and pH7.0. For river waters, the BOD values estimated by the BODst biosensor correlated well with those determined by conventional BOD5 test using artificial wastewater (AWW) as the calibration solution.
Rapid determination of serum melatonin by ESI–MS–MS with direct sample injection
