Anions in non saline waters - Determination of Anions in Natural and Treated Waters - page 308

30 0.831 1.11 0.571 1.20

60 0.722 0.98 0.456 0.98

90 0.679 0.92 0.448 0.95

120 0.613 0.82 0.395 0.84

150 0.561 0.76 0.361 0.77

200 0.419 0.58 0.280 0.60

240 0.328 0.44 0.230 0.48

Source: Reproduced with permission from the Royal Society of Chemistry [815]

2.94.3 Spectrofluorometric methods
A rapid and sensitive method has been developed for the determination of microgram
amounts of sulphide and cyanide [262]. This method depends on the demasking of
quinolin-8-ol-5-sulphonic (1) acid by sulphide from the non-fluorescent potassium bis(5-
sulphoxino)-palladium (2). The liberated quinolin-8-ol-5-sulphonic acid then coordinates
with the magnesium ion present to form a fluorescent chelate (3), which is a measure of
the amount of cyanide or sulphide present. The reactions are shown below.

Table 2.54 Comparison of re-extraction spectrophotometric and methylene blue methods
for the determination of sulphide