Determination Of Cortisol Concentration Found In Plasma Ultrafiltrate, Whole Plasma, and Urine Samples From Farmers Using A Liquid Chromatography-Mass Spectrometry/Mass Spectrometry Procedure

Farmers are at risk of being exposed to pesticides used for neutralizing insects. Long-term exposure of these toxic chemicals can potentially lead to high levels of cortisol in ratio to its metabolite 6β-hydroxycortisol (6β-OH F). Cortisol is a glucocorticoid hormone found in humans; it regulates the metabolism of proteins, lipids, and carbohydrates. However a high cortisol concentration in relation to its metabolite has a direct correlation to one’s stress level, therefore pesticide exposure could potentially lead to stress. In this experimental study plasma ultrafiltrate, whole plasma, and urine samples were taken from local farmers and their immediate families (both adults and children), in order to measure cortisol concentration through the use of a new liquid chromatography- mass spectrometry/mass spectrometry (LC-MS/MS) multiple reactant monitoring (MRM) procedure. In previous years immune-chemical methods such as Radioimmunoassay (RIA) were used instead of LC-MS/MS to measure plasma and urinary cortisol concentration. Although RIA is quite sensitive, it lacks complete specificity because of cross-reaction with other substances in the biological samples; this causes cortisol levels to be slightly overestimated. The LC-MS/MS method avoids the interference of endogenous and exogenous molecules in urine samples, but it has the added value of extreme sensitivity that is more than sufficient for the measurement of plasma free cortisol. The results of this research experiment are anticipated to align with stated predictions based on previous research involving cortisol levels in ratio to its metabolite 6β-OH F and their relation to pesticides and stress levels.