Analysis of the Concentration of Ampicillin in Plasma by Microbial Tube-plate Method
In this experiment,Micrococcus luteus was used as working bacteria,and experiments were conducted according to the growth curve of micrococcus luteus,the preparation of bacterial suspension,the preparation of ampicillin sodium solution,and the preparation of double-layer medium.The results of precision,linear relationship and recovery tests were discussed,and the microbiological method for determining the concentration of ampicillin sodium in plasma was explored.The results showed that in the range of 0.04~5μg/mL,there was a good linear relationship between the logarithm of the concentration of ampicillin sodium and the diameter of the antibacterial zone,r=0.997,and the lowest detection line in plasma was 0.04μg/mL.When ampicillin sodium concentration was 5,0.31 μg/mL and 0.04 μg/mL,the coefficient of variation was 6.55%,7.96%and 7.06%,respectively.The daytime variation coefficients were 5.97%,6.91%and 7.71%,respectively.The recoveries were 97.8%~100%.It is concluded that compared with the instrument method to determine the concentration of ampicillin sodium in plasma,the microbial tube and dish method is reliable,accurate,sensitive,easy to culture and observe the results,and can meet the requirements of plasma ampicillin sodium concentration analysis.