7.4CalculationTheonentofakyphenlethoylatecalculatedamassortonwinmiligramrkgram(mg/kg) of the leather sample according to the following formula: (A, - b) × V axme (1) where As is the peak area of alkylphenol ethoxylate in the extraction solution; bis the intercept ofthe calibration graph; ais the slope of the calibration graph; V is the final volume used according to Z1in millilitres (ml); here 10 ml; me is the weight of the leather sample in grams (g).