Büldt A, Karst U
Abteilung Analytische Chemie, Anorganisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 8, 48149 Münster, Germany.
Anal Chem. 1999 May 1;71(9):1893-8. doi: 10.1021/ac980946f.
The synthesis of N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) and its application as a new reagent for the determination of aldehydes and ketones are described. MNBDH reacts with carbonyl compounds in acidic media to the corresponding MNBD-hydrazones. In contrast to the established reagent 2,4-dinitrophenylhydrazine (DNPH), MNBDH is oxidized by both ozone and nitrogen dioxide quantitatively to only one product, N-methyl-4-amino-7-nitrobenzofurazan (MNBDA). This can easily be separated from the hydrazones of lower aldehydes by means of HPLC. Due to larger molar absorptivities and absorption maxima at wavelengths over 470 nm, selectivity is higher and limits of detection are lower for the new reagent compared to DNPH. MNBDH reacts slightly faster than DNPH with carbonyl compounds and significantly faster than other N-alkylated hydrazine reagents.
描述了N-甲基-4-肼基-7-硝基苯并呋咱（MNBDH）的合成及其作为测定醛和酮的新型试剂的应用。MNBDH在酸性介质中与羰基化合物反应生成相应的MNBD-腙。与已有的试剂2,4-二硝基苯肼（DNPH）相比，MNBDH被臭氧和二氧化氮均定量氧化为仅一种产物，即N-甲基-4-氨基-7-硝基苯并呋咱（MNBDA）。通过高效液相色谱法可轻松将其与低级醛的腙分离。由于新试剂在470 nm以上波长处具有更大的摩尔吸光系数和吸收最大值，与DNPH相比，其选择性更高，检测限更低。MNBDH与羰基化合物的反应速度比DNPH略快，且比其他N-烷基化肼试剂快得多。
