Composition for the colorimetric determination of metals

Claim 1

A diagnostic kit for a colorimetric reagent adapted to the determination of the iron content in blood serum, consisting of two solutions only, the former containing a buffer, a soluble salt of a metal selected from the group comprising the alkali metals and the alkaline earth metals, a soluble form of Chromazurol B, a cationic surface-active agent or a nonionic surface-active agent, the latter solution containing a complexing agent capable of hindering the formation of a complex between the Chromazurol B, the surface-active agent and the iron with the same ingredients of the former solution.

Claim 8

A method for the determination of the iron content of blood serum which comprises: (a) combining a sample of serum with a chromogenic reagent which comprises a buffer; a soluble salt of a metal selected from the group consisting of the alkali metals and alkaline earth metals; a soluble form of Chromazurol B; and a cationic surface-active agent or a nonionic surface-active agent to form a test sample; (b) combining a sample of serum with a masking reagent which comprises a buffer, a soluble salt of a metal selected from the group consisting of the alkali metals and alkaline earth metals; a soluble form of Chromazurol B; a cationic surface-active agent or a nonionic surface-active agent; and a complexing agent capable of hindering the formation of a complex between the Chromazurol B and iron to form a blank sample; (c) combining a standard with the chromogenic agent of step (a) to form a test standard; (d) combining distilled water with the chromogenic reagent of step (a) to form a blank reagent; (e) combining the masking reagent of step (b) with the standard to form a masking blank of step (b); (f) determining the optical density of each of the materials from steps (a), (b), (c), (d), and (e) in a colorimeter; (g) comparing the optical density of the test sample with the test standard after allowance is taken for the optical density of the blank reagent, the blank sample, and the masking blank to determine the amount of iron that is present.

Claim 9

A method for the determination of the iron content of blood serum which comprises: (a) combining a sample of serum with a chromogenic reagent which comprises a buffer; a soluble salt of a metal selected from the group consisting of the alkali metals and alkaline earth metals; a soluble form of Chromazurol B; and a cationic surface-active agent or a nonionic surface-active agent to form a test sample; (b) combining a sample of serum with a masking reagent which comprises a buffer, a soluble salt of a metal selected from the group consisting of the alkali metals and alkaline earth metals; a soluble form of Chromazurol B; a cationic surface-active agent or a nonionic surface-active agent; and a complexing agent capable of hindering the formation of a complex between the Chromazurol B and iron to form a blank sample; (c) combining a standard with the chromogenic agent of step (a) to form a test standard; (d) combining distilled water with the chromogenic reagent of step (a) to form a blank reagent; (e) combining the masking reagent of step (b) with the standard to form a masking blank of step (b); (f) determining the optical density of each of the materials from steps (a), (b), (c), (d), and (e) in a colorimeter; (g) comparing the optical density of the test sample with the test standard after allowance is taken for the optical density of the blank reagent, the blank sample, and the masking blank to determine the amount of iron that is present.