Samira Mumtaz has completed her M.Sc at the age of 22 from The University of Azad Jammu And Kashmir Muzaffarabad. She is the student of M.Phil at The University of Azad Jammu And Kashmir Muzaffarabad. She has completed her M.Phil research work under the supervision of Dr. Tahseen Ghous.


The present work is intended to exploit Flow injection technique for the preconcentration and determination of Cr (VI) in a biosorption column by Staphylococcus aureus staticbiomass immobilized on powdered egg shells as an effective and low cost biosorbent. The procedure is based on the retention of the analyte from buffered solution in a biosorption column and then its elution with NaCl and determination in the form of purple red Cr (VI) comlex with 1,5 diphenylcarbazide at 545 nm in acidic medium. The effect of various parameters such as pH of sample solution, volume of sample, different eluents, their concentrations and flow rate was investigated. The maximum preconcentration of Cr (VI) was achieved at pH 3 at the flow rate 1.2 ml min-1. The proposed method has a linear calibration range from 0.05-100 µgL-1 of Cr (VI) with regression Y= 0.0022x+0.0891 R2=0.987. The limit of detection was 0.05µgL-1 (50ngL-1). This system showed good precession and accuracy with enrichment factor 2.5 for calibration curve 0.05-100 µgL-1with relative standard deviation of 4.4% at 0.05 µgL-1. The sampling frequency was 12 samples h-1. The effect of various cations and anions was studied which have not induced any significant interference in determining Cr (VI).
Keywords: Preconcentration: Biosorption: Eluent: Biomass: Frequency.