title: Flow-through spectrophotometric sensor for the determination of aspartame in low-calorie and dietary products.
abstract: A very simple flow-through sensor is presented for the determination of the intense sweetener aspartame in low-calorie and dietary products. The sensor is implemented in a monochannel flow-injection system with UV spectrophotometric detection using a Sephadex CM-C25 cationic exchanger packed 20 mm high in a flow cell. This method is based on the transient retention of a cationic species of the sweetener on the solid phase when a pH 5.0 acetic acid sodium acetate buffer (0.01 M) is used as a carrier (2.6 mL(-1) min). The carrier itself elutes the analyte from the solid support, regenerating a sensing zone. Aspartame was determined by measuring its intrinsic absorbance at 219 nm at its residence time without any derivatization. Calibration graphs were linear over the range of 5.0 - 600.0 microg mL(-1) with an RSD of 0.55% (peak height). This sweetener was determined in several samples by measuring the height or peak area, obtaining recoveries ranging between 95 - 101% and 97.5 - 101%, respectively. The procedure was validated for its use in the determination of aspartame in low-calorie and dietary products, giving reproducible and accurate results.
authors.affiliation: Department of Analytical Chemistry, Research Group Solid Phase Spectrometry, Faculty of Sciences, University of Granada, Avda, Fuentenueva s/n, E-18071 Granada, Spain. lcapitan@ugr.es
authors.forename: L F
authors.initials: LF
authors.lastname: Capitán-Vallvey
authors.forename: M C
authors.initials: MC
authors.lastname: Valencia
authors.forename: E Arana
authors.initials: EA
authors.lastname: Nicolás
mesh_terms: D001218:Aspartame / Q000032:analysis*; D001628:Beverages / Q000032:analysis*; D017022:Flow Injection Analysis; D005504:Food Analysis / Q000379:methods; D006863:Hydrogen-Ion Concentration; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000295:instrumentation* / Q000379:methods*
chemical_list: D001218:Aspartame