Simultaneous injection effective mixing flow analysis of urinary albumin using dye-binding reaction

• Main Authors: Ratanawimarnwong N., Ponhong K., Teshima N., Nacapricha D., Grudpan K., Sakai T., Motomizu S.
• Format: Conference or Workshop Item
• Language: English
• Published: 2014
• Online Access: http://www.scopus.com/inward/record.url?eid=2-s2.0-84864281015&partnerID=40&md5=84d36b04374644333683795930792197; http://cmuir.cmu.ac.th/handle/6653943832/6761
• Institution: Chiang Mai University

A new four-channel simultaneous injection effective mixing flow analysis (SIEMA) system has been assembled for the determination of urinary albumin. The SIEMA system consisted of a syringe pump, two 5-way cross connectors, four holding coils, five 3-way solenoid valves, a 50-cm long mixing coil and a spectrophotometer. Tetrabromophenol blue anion (TBPB) in Triton X-100 micelle reacted with albumin at pH 3.2 to form a blue ion complex with a λ max 625 nm. TBPB, Triton X-100, acetate buffer and albumin standard solutions were aspirated into four individual holding coils by a syringe pump and then the aspirated zones were simultaneously pushed in the reverse direction to the detector flow cell. Baseline drift, due to adsorption of TBPB-albumin complex on the wall of the hydrophobic PTFE tubing, was minimized by aspiration of Triton X-100 and acetate buffer solutions between samples. The calibration graph was linear in the range of 10-50 μg/mL and the detection limit for albumin (3σ) was 0.53 μg/mL. The RSD (n = 11) at 30 μg/mL was 1.35%. The sample throughput was 37/h. With a 10-fold dilution, interference from urine matrix was removed. The proposed method has advantages in terms of simple automation operation and short analysis time. © 2012 Elsevier B.V. All rights reserved.