Flow-Batch Method with a Sequential Injection System for Spectrophotometric Determination of Selenium(IV) in Selenium-Enriched Yeast Usingo-Phenylenediamine

Abstract A precise, accurate, and reliable flow-batch spectrophotometric method for the determination of selenium (IV) was developed using o-phenylenediamine as a reagent with a sequential injection monosegmented flow system incorporating a simple heating unit. The reaction zones of selenium(IV) and o-phenylenediamine were mixed and heated in a chamber at 62°C for 5 minutes. The piaselanol complexes were then detected at a maximum absorption wavelength of 335 nm. In-line single standard calibration and standard addition procedures were developed employing the monosegmented flow technique. Under the optimized conditions, a linear calibration graph in a range of 0.1–4.0 mg L−1 selenium (IV) was obtained with limits of detection and quantitation of 0.01 and 0.1 mg L−1, respectively. Relative standard deviations were 2% [for both 0.1 and 0.5 mg L−1 selenium (IV) (n = 11)]. A sample throughput of 2 h−1 using four standard addition levels was achieved. The developed system was successfully applied to raw selenium-enriched yeast samples. The analyses performed by the developed method agreed well with those obtained from a standard inductively coupled plasma mass spectrometry method. Keywords: Flow-batch analysisMonosegmented flow o-phenylenediamineSeleniumSelenium-enriched yeastSequential injectionSpectrophotometry Acknowledgments This article is part of a Special Issue on Automated Flow Injection Techniques organized by Dr. Paraskevas Tzanavaras of Aristotelian University of Thessaloniki, Greece. This work was granted by Mahasarakham University for W. Siriangkhawut and P. Chantiratikul. The Thailand Research Fund (TRF) and The Royal Golden Jubilee Ph.D. Program are gratefully acknowledged for scholarship to Y. Khanhuathon. Additional support from the Center of Excellence on Innovation in Analytical Science and Technology (I-ANALY-ST), Chiang Mai University and the Center of Excellence for Innovation in Chemistry (PERCH-CIC), Office of the Higher Education Commission, Ministry of Education are also appreciated. The authors also thank Prof. Gary D. Christian for language editing.