Analysis of Reaction Products of (Ethylenediamine) palladium(Ⅱ) Chloride and 5′-Deoxyguanylic Acid in Aqueous Solution by Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry and Electrospray Ionization Mass Spectrometry / 分析化学

ABSTRACT

A method based on HPLC-ICP-MS was established to separate the reaction products of ( ethylenediamine) palladium(Ⅱ) chloride([Pd ( en ) Cl2])and 5’-deoxyguanylic acid ( 5’-dGMP). Two reaction products were detected at pH 8. 0 with 25 mmol/L phosphate buffer solution as chromatography eluent. One was the main product with HPLC retention time of 2. 8 min, the other product’s retention time was 3.2 min. According to ESI-MS(MS/MS) study, m/z=510, 511, 512, 514, 516[M+1]+ parent ions ( abundances same to palladium isotopes) were detected. Further analysis showed that the main product was[Pd( en) ( N1-5’-dGMP) ]. However the other product was hardly to be detected by ESI-MS. By using HPLC-DAD and HPLC-ICP-MS, we found that the two reaction products had the same UV absorption spectra and palladium percentage content. Combined with other groups’research, the other reaction product was deduced as dimmer, trimer or tetramer form of[Pd( en) ( N1-5’-dGMP) ]. Further study revealed that[Pd( en) ( N1-5’-dGMP) ] was easily formed in acid solution while its polymer form was generated in alkaline solution. At pH 6. 0, [Pd(en)(N1-5’-dGMP)] was formed within 12 hours with good stability. Research also revealed that the total amount of two reaction products declined as reaction pH climbed.