中文摘要：

建立了柱前衍生高效液相色谱-质谱联用（HPLC—MS）测定水稻中尼克烟酰胺含量的方法。样品中尼克烟酰胺经水提取后，与9-芴甲基氯甲酸酯（FMOC—C1）衍生，采用液相色谱质谱联用仪测定。系统研究了衍生剂浓度和衍生介质等条件对衍生效率的影响。通过优化流动相酸度和梯度洗脱等条件，提高了方法灵敏度。尼克烟酰胺在0．1～5．0mg／L范围内呈良好的线性关系（r=0．9983），对水稻的根、茎、叶及大米的标准加入实验表明，方法的添加回收率在72．0％～89．2％之间；相对标准偏差为2．3％～9．6％；方法检出限为0．05mg／kg。方法简便、准确可靠，可以满足水稻中生理水平尼克烟酰胺的定性定量分析。

英文摘要：

A method was developed for the determination of nicotinamide （NA） in rice by pre-column derivatization and high performance liquid chromatography/electrospray ionization mass spectrometry （HPLC/ESI- MS）. After extraction with water, NA was derivatized by 9-fluorenylmethoxyearbonyl（FMOC-CI）. In order to enhance the sensitivity, the derivatization was optimized regarding organic solvent content and amount of FMOC-Cl. The best HPLC conditions for the separation of NA in real samples were achieved using a C18 column and mobile phase which contained 0. 1% formic acid. The MS experiments were performed in selected ion monitoring mode（SIM）. The method shows good linearity over the range of 0. 1 -5 mg,/L for NA with a correlation coefficient of 0. 9983. The limit of determination（LOD） was 0.05 mg/kg. Precision and recovery studies were evaluated at three concentration levels for rice root, stem, leaf and unpolished rice. The recovery （ n = 5） ranged from 72.0% to 89.2% with relative standard deviations from 2.3% to 9.6%. The method is simple, highly selective and reliable, and can be used to determine NA in rice at physiological level.