Characteristics of sulfur response in a micro-flame photometric detector

A recently reported micro-flame photometric detector (μFPD) has been examined in greater detail for its sulfur response characteristics. While supporting an “upside down” flame on a stainless steel capillary burner (delivering oxygen) in a counter flowing stream of premixed hydrogen and oxygen, the extremely small flame of the μFPD (30 nL) was observed to produce linear sulfur emission as HSO*. In this mode, linear sulfur response was obtained over four orders of magnitude with a minimum detectable flow of 2 × 10−10 g S/s. Additionally, a broad series of sulfur compounds ranging in chemical structure were examined in the μFPD in order to determine the extent of equimolarity and reproducibility of response toward this element. Results of exploring both the linear (HSO*) and quadratic (S2*) modes indicate that the %RSD and equimolarity of sulfur response are comparable between that of the μFPD and a conventional flame photometric detector (FPD).