title: Pharmaceutical analysis in solids using front face fluorescence spectroscopy and multivariate calibration with matrix correction by piecewise direct standardization.
abstract: This paper reports the application of piecewise direct standardization (PDS) for matrix correction in front face fluorescence spectroscopy of solids when different excipients are used in a pharmaceutical preparation based on a mixture of acetylsalicylic acid (ASA), paracetamol (acetaminophen) and caffeine. As verified in earlier studies, the use of different excipients and their ratio can cause a displacement, change in fluorescence intensity or band profile. To overcome this important drawback, a standardization strategy was adopted to convert all the excitation-emission fluorescence spectra into those used for model development. An excitation-emission matrix (EEM) for which excitation and emission wavelengths ranging from 265 to 405 nm and 300 to 480 nm, respectively, was used. Excellent results were obtained using unfolded partial least squares (U-PLS), with RMSEP values of 8.2 mg/g, 10.9 mg/g and 2.7 mg/g for ASA, paracetamol and caffeine, respectively, and with relative errors lesser than 5% for the three analytes.
authors.affiliation: Institute of Chemistry, State University of Campinas-UNICAMP, PO Box 6154, 13083-970 Campinas, SP, Brazil. julio@iqm.unicamp.br
authors.forename: Julio Cesar L
authors.initials: JC
authors.lastname: Alves
authors.forename: Ronei J
authors.initials: RJ
authors.lastname: Poppi
mesh_terms: D000082:Acetaminophen / Q000032:analysis*; D018712:Analgesics, Non-Narcotic / Q000032:analysis*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis*; D001241:Aspirin / Q000032:analysis*; D002110:Caffeine / Q000032:analysis*; D002138:Calibration; D000697:Central Nervous System Stimulants / Q000032:analysis*; D016018:Least-Squares Analysis; D013050:Spectrometry, Fluorescence / Q000379:methods* / Q000592:standards
chemical_list: D018712:Analgesics, Non-Narcotic; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000697:Central Nervous System Stimulants; D000082:Acetaminophen; D002110:Caffeine; D001241:Aspirin