Application and Evaluation of Detection for Total Number of Colonies in Water by Paper Method

Objectives To analyze the feasibility and application of detection for total number of colonies in water by paper method.

Methods The repeatability test of 40 different water samples was carried out by paper method. Then paper method and national standard method were simultaneously used to detect the total number of colonies with different types of water samples (n=160), and the result were compared.

Results In the repeatability test, the coefficient of variation of paper method was 1.16%~4.97%. In the comparison experiment, resuls of total number of colonies test with paper method and national standard method were positively correlated (r>0.824, P < 0.001), and there were significant differences in the test result of paper method and national standard method (P < 0.05).

Conclusions Paper method can be used as a trend monitoring of total colonies in water quality or screening method of total number colonies in pollution accidents and emergency hygienic safeguards, because of the correlation result between paper method and national standard method, and the characteristics of simple operation, which is suitable for on-site detection. However, the paper method is still not an alternative to the national standard method.