Primary-Secondary Wavelength Spectrophotometric Determination of Trace Amounts of Lignin Tannin in Water

Abstract

The conventional reaction of lignin and tannin with phospho-wolframate
in the presence of sodium carbonate to form blue complex
has been applied for the determination of trace amounts of
lignin and tannin in water and wastewater by the updated method
named primary-secondary wavelengths spectrophotometry (PSWS).
The results show that the analytical precision and accuracy were
increased and gave higher determining sensitivity than in ordinary
spectrophotometry. The relative standard deviations were less than
3.1 % and the recovery rate of lignin and tannin were between 91.3
and 101 %.