Influence of water content on the laser-induced breakdown spectroscopy analysis of human cell pellet

Abstract

The effects of water content change in a biological sample on the emission signal intensity and intensity ratio during LIBS analysis were investigated. To examine the effects of water content only avoiding matrix effects, a homogeneous human cell pellet consisting of cultured human immortalized keratinocyte cell only was used as the sample. LIBS spectra of the human cell pellet sample produced with a Q-switched Nd:YAG laser (lambda = 532 nm, tau = 5 ns, tophat profile) and a six-channel CCD spectrometer (spectral range = 187-1045 nm, spectral resolution = 0.1 nm) revealed that most of the emission lines observed from a tissue sample were also observable from the human cell pellet. The intensity and intensity ratio of the emission lines varied significantly as the water content of the human cell pellet was changed. It was found that a typically selected internal standard in LIBS analysis of biological samples such as carbon could produce inconsistent results, whereas the ratio of properly selected emission lines such as Mg(II) 280.270 nm and Ca(II) 396.847 nm was nearly independent of sample water content. (C) 2015 Elsevier B.V. All rights reserved.