Test kit for colorimetric analysis

Claim 1

A portable test kit useful in the field for colorimetric analysis of trace levels of a dithizonate complexing metal cation in a aqueous sample, said kit comprising at least one storage tube and lid member assembly, said at least one assembly comprising a storage tube having a conically-shaped end, and being of sufficient volumetric size to serve as a vessel for formation and extraction of an extractable, metal cation-dithizonate complex, and said at least one storage tube and lid member assembly containing a unit dose amount of dithizone in solid form a closed container containing in biphasic liquid form, an organic extractant for said metal cation-dithizonate complex, and an aqueous phase containing accessory test reagents for providing appropriate selectivity, said extractant being of greater density than water and being provided in a volume that provides an at least about 10:1 volume ratio of said aqueous sample to said organic extractant; a sealed, evacuated container means for capturing a portion of a layer formed by colored, dithizonate complex-containing, organic extractant, upon accessing the vacuum in said evacuated container means; a hollow tubular body having an end constructed so as to form an air-tight sealing relationship with said evacuated container means and, when said evacuated container means and said hollow tubular body are in said air-tight sealing relationship, said combination thereof being open to the ambient atmosphere only at another end of said hollow tubular body; and means for providing analysis of the color of said captured layer portion.