Carbonate buffer (A) for the eluent was prepared of 0.43g/L sodium carbonate and 3.04g/L sodium bicarbonate (c = 0.04mol/L; pH 9.1). Carbonate buffer (B) for the sulfite stan-dard solution was prepared of 4.7g/L sodium carbonate and 2.4g/L sodium bicarbonate (c = 0.06mol/L; pH 10.6). Sulfite standard solution contained 0.4mg/L of SO2 in carbonate buffer (pH 10.6) and was stabilized with 0.18g/L EDTA and 0.23g/L fructose.