Effect of detector temperature on flame photometric detector behaviour

Abstract

Detector temperature was studied as a parameter affecting the behaviour of the flame photometric detector towards sulphur and phosphorus compounds using 394 and 526 nm filters, respectively. If was found that while the peak heights of sulphur compounds decrease along with increasing temperature of the flame photometric detector, the peak heights of phosphorus compounds increase. At the same time, the exponent n in the dependence of the peak height on the amount of sulphur compounds also decreases. As the detector noise also increases with the detector temperature, the minimum detectable amount of sulphur compounds increases ca. 2.5 times, while that of phosphorus compounds remains approximately the same. The detector temperature also affects the detection selectivity, the P/S ratio increasing six times in one channel over the temperature range 80–160°C. At a constant detector temperature, the selectivity varies with the air flow-rate by ca. two orders of magnitude. It was shown that errors in the quantitative analysis which had not taken into consideration the effect of the detector temperature on the flame photometric detector response can reach values greater than 100%.