Table 1.

General characteristic of catalytic spectrophotometric methods for the determination of ascorbic acid

Reagent	Method	D.R ( μ g mL -1 )	D.L ( μ g mL -1 )	Real sample	Ref.
Triiodide	FIA d	0.1–40	0.03	Fruits, jam	23
Vanadotungstophosphoric acid-VO3-	FIA	up to 80	1.0	Vitamine C tablet	24
Toluidine blue	Fixed time	3-35	1.3	Fruits and vegetables	25
NaOH	FIA	1–25, 1–50	0.5, 0.2	Fruit juices and pharmaceuticals	26
Prussian Blue	FIA	0.88- 17.6	0.41	Pharmaceutical	27
Copper (II) phosphate	FIA	0.88–7.04	0.053	Pharmaceutical	28
Fe(III)-1,10-phenanthroline	FIA	0.88–10.6	0.088	Pharmaceutical	29
Ferrozine a	FIA	0.5–10	0.028	Pharmaceutical, juices and urine	30
MnO4--H+	FIA	up to 200	-	Vitamin C tablet	31
Rhodamine 6G-Cr2O7-2/I	FIA	0.1–4	0.08	Pharmaceutical, tomato, orange	32
Fe(II) - DPPH b	FIA	5.7–600.0	1.7	Pharmaceutical	33
Methyl Orange-HCl/BrO3-	Fixed time	1.4–211.3	1.3	Pharmaceutical	34
Fe (III) and 2,2′-dipyridyl	FIA	0.5–20	0.22	Rat's tissues	35
Porphyrin-Cu+2	FIA	0.1–1000	0.005	Soft drink	36
Fe(II) - (TPTZ) c	FIA	0.014-1.76	0.0042	Pharmaceutical	37
Orange-G‒BrO3-	Fixed time	0.7–8.3 & 8.3-33.5	0.21	Pharmaceutical, serum and urine	This work

^aFerrozine: 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4′,4″-disulphonate;

^b DPPH: 2,2′-dipyridyl-2-pyridylhydrazone;

^c TPTZ: iron(II) with 2,4,6-tripyridyl-s-triazine; ^d FIA: Flow injection analysis.