Two simple chemometrics methods for spectrophotometric determi ‎nation of trace amounts of beryllium by mean centering of ratio spectra ‎‎(MCRS) and partial least squares (PLS) regression are described. Thorin at ‎pH = 10.5 was used as a chelating agent. The proposed methods evaluate ‎and eliminate the blank bias error present in such procedure. Under the ‎optimized conditions, analytical characteristics of the mean centering of ‎ratio spectra method were obtained. The calibration curve was linear ‎over the range of 10-600 ng mL-1 of Be`.. The concentration detection ‎limit of 2.56 ng mL-1 was achieved. The relative standard deviation for ‎six replicate measurements of 200 ng mL-1 beryllium was 4.0 %, ‎Relative error of prediction for applying the partial least squares method ‎to 5 synthetic samples in the range of 10-600 ng mL-1 was 3.2 %. Analysis ‎of spiked tap water, using both proposed methods, gave results which are ‎in good agreement with their beryllium contents.‎

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