A ultraperformance liquid chromatography–tandem mass spectrometry method has been developed to determine dihydrocodeine (DHC) and dihydromorphine (DHM) in human plasma using dihydrocodeine-d6 and desomorphine as internal standards (IS). Acetonitrile–water–ammonium format was used as the mobile phase, in gradient elution on a C18 column. The concentration of DHC and DHM was determined in the positive ionization mode of mass spectrometry. The total chromatogram run time was 3.2 min, and the linear ranges of DHC and DHM were 1.000–400.0 ng/mL and 0.050–20.00 ng/mL, respectively. The method was fully validated concerning precision, accuracy, selectivity, linearity, recovery, stability and matrix effect. The method had been successfully applied to the bioequivalence test. In addition, we found that a high-fat diet impacts the Tmax and t1/2 of DHC.

中文翻译：

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开发用于二氢可待因和二氢吗啡的灵敏快速 HPLC-MS 方法：在生物等效性研究中的应用

开发了一种超高效液相色谱-串联质谱法，使用二氢可待因-d6 和去甲吗啡作为内标 (IS) 测定人血浆中的二氢可待因 (DHC) 和二氢吗啡 (DHM)。乙腈-水-铵形式用作流动相，在 C18 柱上进行梯度洗脱。DHC和DHM的浓度在质谱的正电离模式下测定。总色谱运行时间为 3.2 分钟，DHC 和 DHM 的线性范围分别为 1.000–400.0 ng/mL 和 0.050–20.00 ng/mL。该方法在精密度、准确度、选择性、线性、回收率、稳定性和基质效应方面得到充分验证。该方法已成功应用于生物等效性试验。此外，我们发现高脂肪饮食会影响 DHC 的 Tmax 和 t1/2。