This standard specifies a method for determining the amount of lithium hydroxide in lithium hydroxide monohydrate, which is suitable for samples with a lithium hydroxide content greater than 50.00%. The method titrates the total alkalinity (TA) of the test solution with muriatic acid standard solution by dissolving the test sample in muriatic acid standard solution, using methyl red-bromocresol green as an indicator. The lithium hydroxide content is calculated by the amount of muriatic acid consumed. At the same time, the content of sodium and potassium in the sample needs to be converted into lithium hydroxide content and deducted from the result. The standard requires the use of analytical pure reagents and deionized water to ensure the accuracy of the measurement results.