Examples include, for example, alkaline metal salt such as a sodium salt, a potassium salt and the like; alkaline-earth metal salt such as a magnesium salt, a calcium salt and the like; organic ammonium salt such as a ammonium salt, a triethyl ammonium salt, tributyl ammonium salt, pyridinium salt and the like; salt of amino acid such as lysine salt, arginine salt and the like.