Since linear sulfur response has also been previously establishedin the mFPD , it was interesting to explore here as well. In par-ticular, since the emitter (HSO*) is oxygenated it was wondered if the additional oxygen supplied to the worker flames may be able to, for example, enhance the formation of this species. In fact, under optimal HSO* conditions, linear sulfur response was found to provide S/N values that were about 5 times greater in the worker flames than in the analytical flame. Further, since HSO*emission was linear over nearly 4 orders of magnitude in each mode, this worker flame enhancement was consistent and yieldedan MDL near 3 × 10−11gS/s, which is within about a factor of 3 to the quadratic mode of Fig 4, and compares well to linear sulfur modes reported in a conventional FPD and pFPD