Determination of total sulfur in lichens by combustion-infrared analysis

Abstract

Sulfur was determined in Parmelia sulcata and P. chlorochroa by combustion of the sample and infrared detection of evolved sulfur dioxide using an automated sulfur analyzer.Vanadium pentoxide was used as a combustion accelerator. Pelletization of the sample prior to combustion was not found advantageous. Washing studies showed that leaching of sulfur was not a major factor in the sample preparation.The combustion-IR analysis usually gave higher sulfur content than the turbidimetric analysis as well as shorter analysis time.Relative standard deviations of less than 7% were obtained by the combustion-IR technique when sulfur levels in lichens ranged from 0.05-0.20%.Determination of sulfur in National Bureau of Standards orchard leaves standard reference material showed good agreement between the combustion-IR technique and other instrumental procedures.

Baseline elemental-composition of selected plants and soils, and assessment of airborne element contamination, Theodore Roosevelt National Park, North Dakota

“…The details of this study and our results are published elsewhere and will not be repeated here (Jackson, Engleman, and Peard, 1985). Thalli of the epiphytic ("air plant") lichen Parmelia sulcata Tayl.…”

“…A detailed description of the results of the lichen thalli cleaning investigation (Study 1), which also includes the development of a new analytical method for the determination of total sulfur by combustion-infrared analysis, is given in Jackson, Engleman, and Peard (1985).…”

“…Each group contained about 25 g of material, and following thorough homogenization, was separated into 16 analytical splits of about 1.5 g each. Each split was analyzed for total sulfur by combustioninfrared photometry (Jackson, Engleman, and Peard, 1985).…”