Determination of NiII(3-OMe-salophene) in MCF7 and HT29 cancer cell lines using HR-CS-AAS and in serum albumin using LC with monolithic silica

A high-resolution continuum source atomic absorption spectrometric method was developed and validated for the determination of Ni-II(3-OMe-salophene) (a complex with anticancer activity in vitro) in MCF7 and HT29 cancer cell lines. The primarily most sensitive line 232.003 nm was selected for analysis. Compared to the standard nickel, the absorbance values obtained for Ni-II(3-OMe-salophene) complex was at least 93% at the upper end of linear range of the calibration curve. The use of common matrix modifiers including magnesium nitrate, palladium nitrate, ammonium hydrogen phosphate, lanthanum chloride and calcium nitrate brought no significant improvement in the GF AAS measurement. The dynamic linear working range of the calibration curve was found to be between 2.16 and 12.0 mu g L-1 (ppb). This covers a concentration range of the complex from 0.036 mu m to 0.204 mu M. Typical coefficients of variation (n = 6) ranged from 0.2% to 6.7% for Ni in Ni-II(3-OMe-salophene). Detection and quantitation limits were 0.65 and 2.16 mu g L (ppb), respectively. The proposed method has been successfully applied to the analysis of Ni-II(3-OMe-salophene) complex in cell lines of breast cancer (MCF7) and colon cancer (HT29). However, being based on the determination of nickel in the salophene complex, the method was unsuitable for the quantitation of Ni-II(3-OMe-salophene) in serum albumin, which originally contains significant amount of nickel. For this purpose, a high performance liquid chromatographic method with a monolithic silica RP-18e column has been developed to quantitate the complex in serum albumin. The developed chromatographic method depends on detecting the whole complex in serum rather than the bounded nickel. A mobile phase consisting of 25 mM phosphate buffer pH 3/methanol (30:70, v/v) was pumped at a flow rate of 1 mL min(-1). The eluted complex was monitored at a wavelength of 250 nm. The dynamic linear working range of the calibration curve for the developed LC method was found to be between 100 and 20,000 mu g L-1 (0.23-46.18 mu M). Detection and quantitation limits were 30 and 100 mu g L-1 (ppb), respectively. (C) 2011 Elsevier B.V. All rights reserved.