[Determination of homocysteine by tandem mass spectrometry with chemical ionization].

Homocysteine (Hcy) is an intermediate of methionine metabolism. High plasma Hcy concentrations are an independent risk factor for stroke, peripheral vascular disease, deep venous thrombosis, coronary disease, and cognitive deficiency. Apparently, it is a great importance to measure Hcy levels in human blood. A new method for the quantification of Hcy by means of reversed-phase LC/atmospheric pressure chemical ionization mass spectrometry has been developed. The MRM ion transition, m/z 136.0 ® 90.0 was used for Hcy quantification. The limit of detection was 0.4 mM, quantification was performed from 1 mM to 40 mM with coefficient of determination of R2=0,997. The method was applied successfully to Hcy determination in human blood. Gomotsistein (Hcy) - promezhutochnyĭ produkt metabolizma metionina. Vysokie kontsentratsii Hcy v krovi iavliaiutsia faktorom riska insul'ta, serdechno-sosudistykh zabolevaniĭ, glubokogo tromboza, koronarnoĭ nedostatochnosti i kognitivnykh defektov. V rabote predlozhen novyĭ metod ékstraktsii i kolichestvennogo opredeleniia Hcy metodom tandemnoĭ khromatomass-spektrometrii s obratno-faznoĭ VÉZhKh. Detektirovanie vypolniali na troĭnom kvadrupol'nom mass-spektrometre Agilent 6410-2K v rezhime detektirovaniia zadannykh mass (MRM) (136,0 ® 90,0) v usloviiakh polozhitel'noĭ khimicheskoĭ ionizatsii pri atmosfernom davlenii (APCI, Positive). Predel obnaruzheniia gomotsisteina sostavil 0,4 mkM. Kalibrovochnaia krivaia lineĭna dlia gomotsisteina v diapazone kontsentratsiĭ ot 0,4 mkM do 40 mkM imeet lineĭnyĭ kharakter s koéffitsientom dostovernosti approksimatsii R2=0,997. Metod uspeshno primenen dlia opredeleniia kontsentratsiĭ gomotsis teina v plazme krovi cheloveka.