Metal ion Reagent
(nm)pH/medium Aqueous/extraction Beer’s law μ g mL−1
L mol−1 cm−1 Interference Reference Fe(II) Thiocyanate-phenanthroline 520 — Aqueous 0–24 1.87 — [10 ] Fe(II) 2-[2-(3,5-Dibromopyridyl-azo]-5-dimethyl amino-benzoic acid 615 2.0–7.0 Extraction 0–5.5 9.36 Tl(I), Zn(II), Cr(III), W(VI), Co(II), Cu(II), Ni(II), and Pd(II) [24 ] Fe(II) 1,10-Phenanthroline and picrate 510 2.0–9.0 Extraction 0.1–3.6 13 EDTA, CN- [25 ] Fe(II) 4-(2-Pyridylazo)resorcinol 505 6.0–7.5 Extraction 0–2.0 6 Ni(II), Co(II), Pb(II), and EDTA [26 ] Fe(II) 1,10-Phenanthroline-tetraphenylborate 515 4.25 Aqueous 2.24–37.29 1.2 — [27 ] Fe(II) 1,3-Diphenyl-4-carboethoxy pyrazole-5-one 525 3.5–4.0 Aqueous 0.5–10 1.156 Cu(II), Co(II), Zn(II), Mo(VI), EDTA [28 ] Fe(II) Dyformyl hydrazine 470 7.3–9.3 Aqueous 0.25–13 0.3258 — [29 ] Fe(II) 4,7-Diphenyl-1,10-phenanthroline and tetraphenylborate 534 — Extraction 0–20.0 2 — [30 ] Fe(II) Thiocyanate-acetone 480 HClO4 Aqueous — 2.1 Cu(II),
, and
[31 ] Fe(II) 2-Hydroxy-1-naphthaldehyde-p-hydroxybenzoic hydrazone 405 5 Aqueous 0.05–1.37 5.6 Sn(II), Co(II) Ni(II) Zn(II) Al(III) Cu(II) Present method Co(II) Sodium isoamyl xanthate 400 4.5–9.0 Aqueous 3.0–35 1.92 [16 ] Co(II) 2-Pyridine carboxalde hydeisonicotinyl-hydrazine 346 9 Aqueous 0.01–2.7 7.1 Au(III), Ag(I), Pt(III) [18 ] Co(II) 2-Hydroxy-1-naphthalidene salicyloyl hydrazone 430 8.0–9.0 Extraction 0–10 0.16 [22 ] Co(II) Pyridine-2-acetaldehyde salicyloyl hydrazone 415 1.0–6.0 Extraction 0.5–7.0 1.04 — [32 ] Co(II) Bis-4-phenyl-3-thiosemicarbazone 400 4 — 0.6–6.0 2.2 — [33 ] Co(II) 2-Hydroxy-l-naphthalidene-salicyloylhydrazone 430 8.0–9.0 Extraction 0–10 1.6 × 103 — [22 ] Co(II) 2-(2-Quinolynylazo)-5-dimethylamino aniline 625 5.5 Extraction 0.01–0.6 4.3 Many cations and anions [34 ] Co(II) 2-Hydroxy-3-methoxy benzaldehyde thiosemicarbazone 390 6 Aqueous 0.06–2.35 2.74 — [35 ] Co(II) 2-Hydroxy-1-naphthaldehyde-p-hydroxybenzoic hydrazone 425 5 Aqueous 0.12–3.54 2.3 Ni(II), Zn(II), Sn(II), In(III), and Ga(IIII) Present method
