Multivariated calibration as a tool for resolution of color from mandarin peel and dyes in aqueous solution for bioadsorption studies

[Display omitted] •Mandarin peel (Citrus reticulata) is used as dye bioadsorbent.•Multivariate calibration is applied for quantification of complex mixtures of dyes with improved accuracy.•Multivariate calibration improves determinations in adsorption process. A spectrophotometric methodology was developed to determine the concentration of four dyes in solutions, after the use of mandarin peel (Citrus reticulata) as adsorbent. Thus, the method entails distinguishing the previous spectral interference of 1 g of mandarin peel through the application of multivariate calibration technique using the Partial Least Squares Regression (PLSR-1) method in determining the concentration of the dyes: Methylene Blue (MB), Crystal Violet (CV), Bright Green (BG) and Methyl Orange (MO). The experimental calibration matrix was designed by measuring the absorbance in the 400−800 nm range for 30 samples of each dye. The quadratic prediction coefficient for MB, CV, BG and MO were above 0.99, as well as the proposed PLS-1 method that was applied to samples with good (RMSEP) precisions (0.1694−0.9281), (0.1964−0.6048), (0.2183−0.7734), (0.0130−0.5856) in mg L−1, respectively. Therefore, the proposed method was successfully applied for the quantification of dye concentrations.