Sequential injection system for simultaneous determination of sucrose and phosphate in cola drinks using paired emitter-detector diode sensor.
This work presents the simultaneous determination of sucrose and phosphate by using sequential injection (SI) system with a low cost paired emitter-detector diode (PEDD) light sensor. The PEDD uses two 890 nm LEDs. Measurement of sucrose in Brix unit was carried out based on the detection of light refraction occurring at the liquid interface (the schlieren effect) between the sucrose solution and water. Phosphate was measured from the formation of calcium phosphate with turbidimetric detection. With careful design of the loading sequence and volume (sample--precipitating reagent--sample), simultaneous detection of sucrose and phosphate was accomplished with the single PEDD detector. At the optimized condition, linear calibrations from 1 to 7 Brix sucrose and from 50 to 200mg PO4(3-)L(-1) were obtained. Good precision at lower than 2% RSD (n=10) for both analytes with satisfactory throughput of 21 injections h(-1) was achieved. The method was successfully applied for the determination of sucrose and phosphate in cola drinks. The proposed method is readily applicable for automation and is found to be an alternative method to conventional procedures for on-line quality control process in cola drink industry.
Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Thailand; Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
Phoonthawee
P
Saetear
Kittiwut
K
Khamtau
Nuanlaor
N
Ratanawimarnwong
Kamonthip
K
Sereenonchai
Duangjai
D
Nacapricha
D001718:Birefringence; D002138:Calibration; D002253:Carbonated Beverages / Q000032:analysis*; D030221:Cola; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods*; D008027:Light; D009391:Nephelometry and Turbidimetry; D010710:Phosphates / Q000032:analysis*; D013395:Sucrose / Q000032:analysis*
D010710:Phosphates; D013395:Sucrose
Cola drinks; Paired emitter-detector diode (PEDD); Phosphate; Schlieren effect; Sucrose; Turbidimetry