| dc.description | In atomic and molecular flame spectroscopy, with combustion flames and plasma, the quality of analytical results for liquid samples is limited by the means of sample introduction, especially when sample flow rates are small. In this project, electrospray was examined as a method to introduce small liquid flows (typically 10 $\mu$L/min) into a flame photometric detector (FPD). This method was used to introduce ionic and nonionic sulphur and phosphorus compounds as well as ionic metal compounds into the FPD. Atomic lines or molecular band spectra from a variety of elements (K, Sr, Sc, S, P, Mn, Mg, Ni, Cu, B, Se, As) were recorded. To demonstrate the potential of electrospray as a new sample introduction technique for the FPD, mass detection limits of selected elements were measured. Detection limits varied from 0.6 ng Cu/s to 18 ng In/s. The dynamic range for Cu was about two and half decades. The application of the electrospray-FPD for phosphorus and sulphur analysis in biological samples was confirmed by obtaining the phosphorus spectra for adenosine 5$\sp\prime$-monophosphate (AMP), DNA, lecithin, and sulphur spectrum for glutathione. The phosphorus dynamic range (AMP) was more than two and half orders of magnitude while a quadratic response with two decades for sulphur (glutathione) was obtained. The detection limit for sulphur was 1 ng S/s. The signal to noise ratio for P and Cu increased at lower flow rates, suggesting that detection limits could be improved with lower flows. | en_US |
