Understanding of peak deterioration in hyphenated speciation systems due to gas-liquid separation in the hydride...

In hyphenated speciation systems with a hydride generation interface one of the processes influencing peak deterioration is gas-liquid separation. A mathematical model was developed to calculate attenuation, signal tailing and resolution loss of HPLC peaks due to gas-liquid separation. It was shown experimentally--using an HPLC-hydride generation-atomic fluorescence spectrometry system for arsenic speciation--that the mathematical model predicts peak deterioration well. This allowed us to study the parameters influencing the deterioration, viz. gas-liquid separation parameters (gas-liquid separator head space volume and purge gas volume flow-rate) and HPLC peak parameters [width (ratio) and resolution] theoretically, simulating HPLC peaks with gaussian functions.