Patent ID: 8785207

Claim:
A method for measuring multiple parameters in-situ in a sample collected from an environmental system via a single device, comprising: receiving a constant flow of said sample at a mass spectrometer of said single device from a syringe pump of said single device; heating a first portion of said sample within a first membrane inlet assembly coupled to said syringe pump to pervaporate said sample through a semi-permeable membrane into a gas phase of said first portion of said sample; measuring, via said mass spectrometer within said single device, a total carbon dioxide gas dissolved (pCO 2 ) in said gas phase of said sample for a carbon system in-situ via said single device; feeding a second portion of said sample out of said first membrane inlet assembly via a fluidic tee positioned between said first membrane inlet assembly and a second membrane inlet assembly; adding a reagent to said second portion of said sample within said single device to create a reagent infused sample; heating said reagent infused sample to pervaporate said reagent infused sample within said second membrane inlet assembly into a gas phase of said reagent infused sample; switching a stream selector valve coupled to said first membrane inlet assembly, said second membrane inlet and said mass spectrometer to feed said mass spectrometer with said gas phase of said reagent infused sample; measuring a total inorganic carbon (DIC) or a total alkalinity (TA) in said sample for said carbon system in-situ via said mass spectrometer within said single device using said reagent infused sample; and calculating a pH of said environmental system using the pCO 2 that is measured and the DIC or the TA that is measured.