Suspended biomass bioreactors can be operated to remove H2S from biogas under anoxic conditions and produce elemental sulfur, the commercial value of which has been demonstrated. In the present paper, a novel methodology comprising the optimization of a determination method performed in a gas chromatograph equipped with a pulsed flame photometric detector (GC-PFPD), combined with a simple preparation based on filtration and extraction with toluene, is proposed. The injector temperature and carrier gas flow rate (QHe) values were optimized using a response surface methodology based on a face-centred composite central design. This optimization revealed that the optimum conditions were an injector temperature and carrier gas flow rate of 222 °C and 7 mL min-1, respectively. The chromatographic method shows an analysis time of 48 min, a detection limit of more than 5.9 mg L-1, a relative standard deviation of less than 3.71%, and a sulfur recovery percentage of more than 98%. These values provide excellent linearity and a reasonable concentration range (10-200 mg L-1). Finally, a measurement error of 4.45% was obtained when using the present method in a selectivity test.
Keywords: Biogenic sulfur; Filtration; GC-PFPD; Response surface methodology (RSM); Toluene.
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