Reagent

λ_max

(nm)

 e × 10⁴

 L/mol.cm

Linear range

(µg/ml)

Ref.

3,3`-(1,3-Propanediyldiimine)bis-[3-methyl-2-butanone]dioxime

525

2.95

0.5- 350

[57]

Bis(acetylacetone)ethylenediimine

370

--

up to 80

[58]

2-(5-Bromo-2-pyridylazo)-5-diethylamino amino phenol, polyglycol octylphenyl ether

560

15

0.0-18

[59]

1,5-Bis(di-2-pyridylmethylene) thiocarbonohydrazide

500

4.2

--

[60]

Diethyldithiocarbamate, β-cyclodextrin

436

1.3

0-6.0

[61]

3-{2-[2-(2-Hydroxyimino-1-methyl-propylideneamino)-ethylamino]-ethyl-imino}-butan-2-one oxime

570

0.16

0.2-225

[62]

Poly[allylamine-co-N-4-(8-aminoquinolyl -5-azo)benzylideneallylamine]

590

4.1

0-l.0

[63]

Dimethylindodicarbocyanine

650

12

0.0-1.2

[64]

1-[Pyridyl-(2)-azo]-naphthol-(2), TX-100, N,N`-diphenylbenzamidine up

520

11.4

to 0.6

[65]

S,S`-bis(2-aminophenyl)oxalate

504

0.54

0.4-150

[66]

Thiomichlersketone, polyethylene octyl phenyl ether

500

5.7

0-0.6

[67]

Naphthazarin

330

1.84

up to 4.5

[68]

bromosulphonazo III

616.8

33

0-1.024

[69]

1-Phenyl-1,2-propanedione-2-oxime thiosemi-carbazone

465

0.56

0.38-7.63

[70]

Triammonium salt of aurintricarboxylic acid

538

192

0.0075 - 0.22

This work