| Technique | Analytes | Matrix(% Recovery) | System | Eluent | PF | Detection limit (μg L−1) | R.S.D (%) | Optimum operating    condition | Reference | 
      
        | FAAS | Cu, Fe, Pb, Mn, Zn,Cd, Ni, Bi, Cr |  | Co-DEDTC | 1.0 mL conc. HNO3 | 225 | 4–64 | <7 | pH: | [32] | 
      
        | Amount of carrier    element (mg): | 
      
        | Amount of chelating    agent(mg): | 
      
        | Sample volume (mL): | 
      
        | FAAS | Pb, Cd, Cr, Ni, Mn | Water(96 – 98) | Cu- DBDTC | 0.5 mL conc. HNO3 | 50 | 0.34–0.87 | <10 | pH:                                                     9 | [33] | 
      
        | Amount of carrier    element (mg):    1 | 
      
        | Amount of chelating    agent(mg):     10 | 
      
        | Sample volume    (mL):                     25 | 
      
        | FAAS | Cd, Cu, Pb | Water( 88.6 -103.5) | Bi(III)4-MPDTC | 1 mL conc. HNO3 | 200 | 0.18-0.50 | <10 | pH:                                                   5 | [26] | 
      
        | Amount of carrier    element (mg): 4 | 
      
        | Amount of chelating    agent(mg): 400 | 
      
        | Sample volume    (mL):                  250 | 
      
        | FAAS | Ni, Cr, Mn, Pb, Zn | Water (96.8-100)        Sediment (97.3-99.2) | Cu-cHMDTC | 0.5 mL conc. HNO3 | 10 | 0.003-0.10 | <17 | pH:                                                9 | [28] | 
      
        | Amount of carrier    element (mg): 1 | 
      
        | Amount of chelating    agent(mg): 10 | 
      
        | Sample volume    (mL):                 25 | 
      
        | FAAS | Ni | Water (89.5 ± 1.3) Sediment (90.2 ± 0.3)
 | Cu-MBDTC | 1.0 mL conc. HNO3 | 10 | 0.003-0.006 | < 5 | pH:    9 | This study | 
      
        | Cr | Water (93.2 ± 2.1) Sediment (87.2 ± 1.1)
 | Amount of carrier    element (mg): 1 | 
      
        | Co | Water (92.1 ± 2.4) Sediment (89.0 ± 0.5)
 | Amount of chelating    agent(mg): 10 | 
      
        | Mn | Water (89.7 ± 0.5) Sediment (92.7 ± 0.4)
 | Sample volume    (mL):                 10 |