Tin Standard Solution (5 ppm Sn)

Dissolve tin R equivalent to 0.500 g of Sn in a mixture of 5 mL of water R and 25 mL of hydrochloric acid R and dilute to 1000.0 mL with water R. Dilute the solution to 100 times its volume with a 2.5 per cent V/V solution of hydrochloric acid R immediately before use.