Laser-induced breakdown spectroscopy of blood serum

Abstract

Electrolytes present in the blood regulate many different and important internal processes such as contractions of the heart. Small variations in the concentrations of these elements can often cause serious health problems. Unfortunately, current detection methods, while quick, require different tests for each of the electrolytes and often use large volumes of reagents, which can prove costly in the long run. In an effort to develop a quick and cost-effective technique we tested laser-induced breakdown spectroscopy (LIBS) as a method of determining concentrations of Na, K, Mg, Ca, and Fe found in pig's blood serum. LIBS causes a plasma to be formed by firing a laser onto a sample and vaporizing a few ng of the target which can then be studied by analyzing the light emitted. All five elements were tested first in water to optimize the experimental conditions (both environmental and those due to equipment) and then in blood serum. We will discuss how the laser-induced plasmas (LIP) formed from blood serum differ from water, the variability and sensitivity of the results in blood. Our results showed large increases in signal strength and smaller increases in shot-to-shot variability for Na, K, Mg, and Ca in pig's blood serum. We also found that while LIBS is not sensitive enough to detect the concentrations of Fe in blood serum, the coupling of LIBS with laser excitation atomic fluorescence (LEAF) could be used instead.