A sample catching system for cleaning a drilling fluid in a drilling operation includes a first line having a first entrance valve configured to allow the drilling fluid to flow into the first line, a first chemical sensor for measuring the amount of hydrogen sulfide of the drilling fluid in the first line, and a first sample catch valve configured to allow the drilling fluid to flow out of the first line. The system also includes a second line having a second entrance valve configured to allow the drilling fluid to flow into the second line, a sample catch pump, and a controller configured to determine the amount of hydrogen sulfide is above a predetermined threshold value, and open the second entrance valve to divert drilling fluid intake from the first line to the second line, and close the first entrance valve to stop the drilling fluid from entering the first line.