Folin's reagent

Structural formula
General
Surname	Folin's reagent
other names	1,2-Naphthoquinone-4-sulfonic acid sodium salt; 3,4-Dihydro-3,4-dioxo-1-naphthalenesulfonic acid, sodium salt; Folin's reagent;
Molecular formula	C 10 H 5 NaO 5 S
Brief description	orange solid
External identifiers / databases
EC number	208-308-9
ECHA InfoCard	100.007.555
PubChem	516996
Wikidata	Q5464387
properties
Molar mass	260.20 g mol −1
Physical state	firmly
Melting point	289 ° C
solubility	soluble in water (50 g l −1 at 20 ° C)
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

The Folin reagent , synonymous with sodium 1,2-naphthoquinone-4-sulfonate, is a detection reagent for amines including amino acids from the group of naphthoquinones . Several detection reagents are known under this name, for example an aqueous solution with ammonium sulfate , uranyl acetate and acetic acid for uric acid detection. The Folin reagent is also not identical to the Folin-Ciocalteu reagent and the Folin-Denis reagent . It was named after the Swedish-American biochemist Otto Knut Olof Folin (1867–1934).

properties

In an alkaline environment, the Folin reagent reacts with amines to form a fluorescent dye. Sodium 1,2-naphthoquinone-4-sulfonate is orange and water-soluble at 50 g / l.

Applications

The Folin reagent is used for the photometric determination of amino acids . It is also used to distinguish MDMA from other amphetamines .

substance	Color change
MDMA	pink
MDE	No reaction
MDA	yellow
BZP	Orange red
TFMPP	Pink
Methylone	No reaction
Methamphetamine	pink
amphetamine	Light orange
PMA	Light yellow
PMMA	Light orange
Ketamine	No reaction
mescaline	No reaction
cocaine	No reaction
ASS	No reaction
Cane sugar	No reaction

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h data sheet Sodium 1,2-naphthoquinone-4-sulfonate, for spectrophotometric det. of isonicotic hydrazide, amines and amino acids, ≥97.0% (T) from Sigma-Aldrich , accessed on February 15, 2017 ( PDF ).
↑ Entry on Folin reagent. In: Römpp Online . Georg Thieme Verlag, accessed on February 16, 2017.
↑ Elsevier's Dictionary of Chemoetymology: The Whys and Whences of Chemical Nomenclature and Terminology . Elsevier, 2006, ISBN 978-0-08-048881-3 , pp. 150 ( books.google.de ).
↑ Kobayashi Y, Kubo H, Kinoshita T: Fluorometric determination of guanidino compounds by new postcolumn derivatization system using reversed-phase ion-pair high-performance liquid chromatography . In: Anal. Biochem. . 160, No. 2, 1987, pp. 392-8. doi : 10.1016 / 0003-2697 (87) 90066-2 . PMID 3578768 .
↑ ^a ^b Folin Reagent Testing Kit . Dance Safe. June 2015. Retrieved August 8, 2015.

[Sigma-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h data sheet Sodium 1,2-naphthoquinone-4-sulfonate, for spectrophotometric det. of isonicotic hydrazide, amines and amino acids, ≥97.0% (T) from Sigma-Aldrich , accessed on February 15, 2017 ( PDF ).

[RömppOnline-2] Entry on Folin reagent. In: Römpp Online . Georg Thieme Verlag, accessed on February 16, 2017.

[3] Elsevier's Dictionary of Chemoetymology: The Whys and Whences of Chemical Nomenclature and Terminology . Elsevier, 2006, ISBN 978-0-08-048881-3 , pp. 150 ( books.google.de ).

[4] Kobayashi Y, Kubo H, Kinoshita T: Fluorometric determination of guanidino compounds by new postcolumn derivatization system using reversed-phase ion-pair high-performance liquid chromatography . In: Anal. Biochem. . 160, No. 2, 1987, pp. 392-8. doi : 10.1016 / 0003-2697 (87) 90066-2 . PMID 3578768 .

[Dancesafe_Folin-5] Folin Reagent Testing Kit . Dance Safe. June 2015. Retrieved August 8, 2015.