brush. Continue the distillation for 5 min., then remove the source of heat, and allow the receiving tube to cool to room temperature. If any droplets of water are adhering to the walls of the receiving tube, Scrub them down with a brush. When the water and toluene have been separated, read the volume of water. 7.4 Calculation Water content, % by mass = V x Where V = volume of water, ml d = density of water W = mass of the test sample, (g) 8- Bacterial count (microbiological count) test The test shall be carried out according to the Gulf standard mentioned in (2.2). 9 – Detection of disease cause bacteria The test shall be carried out according to standard mentioned in items 2.3,2.4,2.5and 2.6.