ABSTRACT
Merck supply a range of test kits covering many different determinands (Table 14.1). Test strips and test kits, both visual and photometric are available and all are suitable for use in the field.
These consist of a reactive test zone firmly bonded to a plastic backing. The test zone is impregnated with reagents, buffers and other substances. The strips are used for rapid exploratory testing of substance con centrations as low as 1 mg L _1. To test a sample the test zone is immersed in the water sample for 1-2 s and matched against a colour scale.
