Device and method for measuring nitrite ions in milk powder

The invention discloses a device and a method for measuring nitrite ions in milk powder. The device comprises a sample injector, a quantitative loop, an infusion pump A, a guard column, a separation column, an infusion pump B, a derivative reaction tube, an ultraviolet and visible spectrophotometer, a waste liquor bottle and a six-way valve, wherein the sample injector is connected with the six-way valve; the six-way valve is connected with the infusion pump and the guard column; the separation column is connected with a tee joint and then is connected with the infusion pump B; the tee joint is sequentially connected with the derivative reaction tube, the ultraviolet and visible spectrophotometer and the waste liquor bottle. A conventional anion exchange analytical column is used for realizing separation of the nitrite ions; compared with reported separation methods, ion exchange chromatography has relatively high separation capability, is generally applied to separating ions with similar properties, thus can