【求助】为什么在试液配制中要加入氢氧化钠溶液？

USP33焦锑酸钾试液

中国药典2010年版：焦锑酸钾试液取焦锑酸钾2g，在85ml热水中溶解，迅速冷却，加入氢氧化钾溶液（3→20）10ml；放置24小时，滤过，加水稀释至100ml，即得。与 USP32一致（Potassium Pyroantimonate TS —Dissolve 2 g of potassium pyroantimonate in 85 mL of hot water. Cool quickly, and add 10 mL of a solution of potassium hydroxide (3 in 20). Allow to stand for 24 hours, filter, and dilute with water to 100 mL. ）
但是USP33为Potassium Pyroantimonate TS —Dissolve 2 g of potassium pyroantimonate in 85 mL of hot water. Cool quickly, and add a solution containing 2.5 g of potassium hydroxide in 50 mL of water and 1 mL of sodium hydroxide solution (8.5 in 100). Allow to stand for 24 hours, filter, and dilute with water to 150 mL.
请教各位高手：焦锑酸钾试液用来做钠盐鉴别，那为什么在试液配制中要加入氢氧化钠溶液？