Ferrozine

The title of this article is ambiguous. The yellow blood liquor salt potassium hexacyanidoferrate (II) is also called ferrozine in oenology

Structural formula
Sodium salt of ferrozine
General
Surname	Ferrozine
other names	Disodium 4- [3-pyridin-2-yl-6- (4-sulfonatophenyl) -1,2,4-triazin-5-yl] benzosulfonate ( IUPAC )
Molecular formula	C 20 H 12 N 4 Na 2 O 6 S 2 • x H 2 O
Brief description	yellow, odorless powder
External identifiers / databases
CAS number 28048-33-1 EC number 248-797-6 ECHA InfoCard 100.044.346 PubChem 34127 Wikidata Q1408061
properties
Molar mass	492.46 g mol −1
Physical state	firmly
Melting point	> 300 ° C
solubility	soluble in water
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
Toxicological data	> 316 mg kg −1 ( LD 50 , quail ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Ferrozine is an organic chemical compound from the group of arenesulfonic acid salts . The aqueous solution serves as a reagent for the photometric determination of iron .

Use in serum iron determination

The iron contained in the blood is not free, in the form of ions, but in proteins such as B. hemoglobin or the transferrin bound. If blood is collected without anticoagulants, it clumps together. The remaining liquid is called serum . The serum normally contains 1 µg Fe per milliliter, which is bound to transferrin . To determine the serum iron concentration, three work processes are necessary for which complexation by ferrozine is essential.

Step 1: Fe ³⁺ in transferrin is reduced to Fe ²⁺ and thereby removed from the protein. Most commonly used reducing agents are hydroxylamine hydrochloride , ascorbic acid or, as in the following example, thioglycolic acid :

${\displaystyle \mathrm {2\ Fe^{3+}+2\ HS{\text{-}}CH_{2}{\text{-}}COOH\rightarrow } }$ ${\displaystyle \mathrm {2\ Fe^{2+}+HOOC{\text{-}}CH_{2}{\text{-}}S{\text{-}}S{\text{-}}CH_{2}{\text{-}}COOH} }$

Step 2: Trichloroacetic acid is added for the precipitation of all proteins, whereby Fe ²⁺ remains in solution. The proteins are then removed by centrifugation. If proteins remained in solution, they would be partially precipitated in solution during spectrophotometry . Light scattering on the particles of the precipitate could then lead to errors in the extinction measurement.

general:

${\displaystyle \mathrm {Protein(aq){\xrightarrow {CCl_{3}CO_{2}H}}Protein(s)} }$

Step 3: A defined volume of the supernatant liquid from step 2 is transferred to a fresh vessel and an excess of ferrozine is added to form the purple complex, the extinction of which is measured (between 550 and 600 nm maximum absorption). In addition, the solution is buffered in order to bring the pH to the range of complete complexation of the ferrozine-iron complex.

${\displaystyle \mathrm {Fe^{2+}+3\ Ferrozin^{2-}\rightarrow (Ferrozin)_{3}Fe^{4-}} }$

In the serum iron determination just described, the values ​​determined are about 10% too high, since copper as a trace element in the serum can also react with ferrozine. This interference can be eliminated by adding neocuproin or thiourea . Since these reagents can form very strong complexes with copper, they are masked .

literature

• Daniel C. Harris: Textbook of Quantitative Analysis , 1995.

Individual evidence

1. ↑ Erbslöh Greisenheim: Datasheet Ferrozin ( Memento of the original from February 18, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . 
2. ↑ ^{a b} Ferrozin data sheet at Acros, accessed on February 26, 2010.
3. ↑ entry to Ferrozin at ChemBlink , accessed on 26 February, 2010.
4. ↑ ^{a b} Ferrospectral® data sheet (PDF) from Merck , accessed April 1, 2011.
5. ↑ Entry on ferrozine in the ChemIDplus database of the United States National Library of Medicine (NLM) .
6. ↑ Ecotoxicology and Environmental Safety . Vol. 6, p. 149, 1982.