title: Simultaneous multicomponent spectrophotometric monitoring of methyl and propyl parabens using multivariate statistical methods after their preconcentration by robust ionic liquid-based dispersive liquid-liquid microextraction.
abstract: A powerful and efficient signal-preprocessing technique that combines local and multiscale properties of the wavelet prism with the global filtering capability of orthogonal signal correction (OSC) is applied for pretreatment of spectroscopic data of parabens as model compounds after their preconcentration by robust ionic liquid-based dispersive liquid-liquid microextraction method (IL-DLLME). In the proposed technique, a mixture of a water-immiscible ionic liquid (as extraction solvent) [Hmim][PF6] and disperser solvent is injected into an aqueous sample solution containing one of the IL's ions, NaPF6, as extraction solvent and common ion source. After preconcentration, the absorbance of the extracted compounds was measured in the wavelength range of 200-700 nm. The wavelet orthogonal signal correction with partial least squares (WOSC-PLS) method was then applied for simultaneous determination of each individual compound. Effective parameters, such as amount of IL, volume of the disperser solvent and amount of NaPF6, were inspected by central composite design to identify the most important parameters and their interactions. The effect of pH on the sensitivity and selectivity was studied according to the net analyte signal (NAS) for each component. Under optimum conditions, enrichment factors of the studied compounds were 75 for methyl paraben (MP) and 71 for propyl paraben (PP). Limits of detection for MP and PP were 4.2 and 4.8 ng mL(-)(1), respectively. The root mean square errors of prediction for MP and PP were 0.1046 and 0.1275 μg mL(-)(1), respectively. The practical applicability of the developed method was examined using hygienic, cosmetic, pharmaceutical and natural water samples.
authors: School of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran.
authors: Rouhollah
authors: R
authors: Khani
authors: Department of Chemistry, Faculty of Sciences, K.N. Toosi University of Technology, Tehran 16617, Iran.
authors: Jahan B
authors: JB
authors: Ghasemi
authors: School of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran. Electronic address: Shemiran@khayam.ut.ac.ir.
authors: Farzaneh
authors: F
authors: Shemirani
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D006795:Household Products / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry*; D016018:Least-Squares Analysis; D059627:Liquid Phase Microextraction / Q000379:methods*; D015999:Multivariate Analysis; D010226:Parabens / Q000032:analysis*; D012492:Salts / Q000032:analysis; D012996:Solutions; D012997:Solvents; D013053:Spectrophotometry / Q000379:methods*; D014867:Water / Q000737:chemistry; D058067:Wavelet Analysis
chemical_list: D052578:Ionic Liquids; D010226:Parabens; D012492:Salts; D012996:Solutions; D012997:Solvents; D014867:Water; C015358:methylparaben; C006068:propylparaben
keywords: Ionic liquid-based dispersive liquid–liquid microextraction; Parabens; Partial least squares; Personal care products; Simultaneous analysis; Wavelet orthogonal signal correction