A new, simple, and accurate carrier element-free coprecipitation method has been developed to separate and preconcentrate of Cd(II), Cu(II), Ni(II), and Pb(II) ions from water and food samples. The proposed method was based on utilisation of 3-benzyl-4-p-nitrobenzylidenamino-4,5-dihydro-1,2,4-triazole-5-thiol (BNBATT) as a new organic co-precipitant at pH 7.0 and the determination of the metal ions being examined using FAAS. To recover the metal ions analysed, The influencce of many parameters including pH, sample volume, co-precipitant quantity, and the rate and time of centrifugation, was tested. There was also monitoring the effect of matrix ions, and no interferences were found. The validity of the proposed method was verified by test of certified reference materials. The analyte ions recovery values were measured and found to be in the range of 95–100%. The relative standard deviation (RSD%) was measured to determine the precision of the proposed approach and was found to be ≤ 5.0%. The limits of detection (K = 3.0, N = 10), were determined in the range of 0.3–0.8 μg L−1. The calculated preconcentration factor was 100 for Cd(II), Cu(II) and Ni(II) and 80 for Pb(II). Satisfactory results for separation and preconcentration trace amounts of the studied metal ions in water, food, and certified reference materials samples.