2-hydrazino-l-methylpyridine

Higashi and coworkers [28] used 2-hydrazino-l-methylpyridine (HMP) derivatization to introduce a positively charged moiety in testosterone and dihydrotestosterone (DHT) to achieve a sensitivity improvement of 70- to 1600-fold compared to underivatized molecules in ESI. However, they found the derivative was unsuitable for di-keto steroids such as androstenedione and progesterone, so this form of derivatization is unlikely to be widely accepted. Separable syn- and anti- (E and Z) stereoisomers are formed using this derivative. Preparation is as follows a solution of 10 pg HMP in 50 pi ethanol containing 25 pg TFA was added to the steroid dissolved in 30 pi ethanol. After heating for 1 h at 60 C, the solvents can be removed and sample injected. 

Higashi T, Yamauchi A, Shimada (2005b) 2-Hydrazino-l-methylpyridine a highly sensitive derivatization reagent for oxosteroids in liquid chromatography-electrospray ionization-mass spectrometry. J Chromatogr 825 214-222... 

Human prostate (10 mg tissue) extraction (70% methanol) PR-SPE derivatization with 2-hydrazino-l-methylpyridine... 

T IS ds-T Rat brain (100 mg) extraction (methanol-acetic acid) RP-SPE preparative NP-HPLC derivatization with 2-hydrazino-l-methylpyridine Rat serum (50 p,l) deproteinization (methanol-acetic acid) RP-SPE derivatization with 2-hydrazino-l-methylpyridine J sphere ODS H-80 (150 X 2.0 mm I.D., YMC), acetonitrile-methanol-10 mM ammonium formate and 0.2 ml/min API 2000 (Applied Biosystems), positive ESI, SRM ([M]+ residual [M]+) LOQ 0.06 ng/g tissue (brain) and 0.06 ng/ml (serum) [37]... 

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