1. Pipette 1 ml of clear urine into a test tube of the same size as the small standard tubes. If the urine is cloudy, filter or centrifuge it to obtain a clear sample for testing.
2. Add 1 ml of acidified silver nitrate reagent to the urine and mix. Caution: The reagent is corrosive. Also handle it
with care because although colourless it will stain skin, clothes, bench surfaces, etc, and the brown colour is difficult to remove.
3. Examine the urine for a cloudiness. Estimate the approximate concentration of chloride in the urine by matching the cloudiness with the standards. Matching is best carried out against a dark background.
4. Report the approximate chloride concentration in the urine in mmol/l.
If the urine remains clear after adding the reagent report the test as ‘no chloride detected’. Use a ‘normal’ urine as a positive control.
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