目的 建立测定二甲苯磺酸拉帕替尼片有关物质的高效液相色谱法。方法 采用Waters Xterra MS C₁₈色谱柱（4.6 mm×250 mm，5 μm）；以0.01 mol·L^-1磷酸二氢钠溶液（用磷酸调节pH值至3.2）为流动相A，以乙腈为流动相B，梯度洗脱，流速1.0 mL·min^-1；检测波长265 nm，柱温40 ℃。结果 拉帕替尼杂质A、拉帕替尼杂质2和拉帕替尼杂质1分别在0.02～8.08、0.02～8.26和0.02～8.29 mg·mL^-1内线性关系良好， r≥0.999 9，定量限分别为1.0、1.4、2.1 ng，杂质高、中、低浓度的平均回收率（n=9）在100.2%～102.9%，RSD（n=9）在0.02%～0.66%，可以满足杂质分析的要求。结论 本方法简便、准确、专属性强，可定量测定二甲苯磺酸拉帕替尼片的有关物质。

OBJECTIVE To establish a determination method of the related substances of lapatinib ditosylate tablets by HPLC. METHODS Waters Xterra MS C₁₈ column (4.6 mm×250 mm， 5 μm) was selected； 0.01 mol·L^-1 sodium dihydrogen phosphate solution (pH adjusted to 3.2 with phosphoric acid) was mobile phase A， acetonitrile was mobile phase B， and gradient elution was used at a flow rate of 1.0 mL·min^-1. The detection wavelength was set at 265 nm， and the column temperature was 40 ℃. RESULTS Lapatinib Impurity A， LAPA-2 and LAPA-1 had good linearity in the range of 0.02-8.08， 0.02-8.26 and 0.02-8.29 mg·mL^-1， respectively (r ≥ 0.999 9). The limits of quantitation (LOQ) were 1.0， 1.4， and 2.1 ng， respectively. The average recovery (n=9) was in the range of 100.2%-102.9%， and RSDs (n=9) were in the range of 0.02%-0.66%. CONCLUSION The method is simple， accurate， and specific and can quantitatively determine the related substances of lapatinib ditosylate tablets.