Oxalic acid was obtained by treating buckwheat husks with dilute nitric acid. Its structure was confirmed with EA,IR and MS analysis.

• 荞麦皮经稀硝酸处理后，从滤液中得到一种透明的针状晶体。该晶体经元素分析、红外光谱及质谱测定，确认为草酸。