Abstract: A method for testing blood samples for determining lead content therein. The method utilizes filter collection paper that is spotted with a blood sample; the blood sample spotted thereon is allowed to dry. The dried blood sample on the paper is punched out in a predefined manner to obtain a uniform volume equivalent to a predefined volume of whole blood. A dilute aqueous acid reagent containing a surfactant wetting agent is utilized to remove the part of the blood sample containing the lead. The filter collection paper retains the hemoglobin and blood proteins thus yielding a protein free solution that is suitable for direct analysis of the trace lead elements. The dried blood sample may be easily stored and economically transported to testing laboratories where the dried blood sample may be eluted into a hemoglobin and protein free solution that is stable for weeks under proper storage conditions.

Abstract: A flow cell for location intermediate a light source and a photosensitive device for light measurement of a fluid therein in a light path. The flow cell has an elongated tubular body member, a debubbler unit, and a tubular fluid outlet tower. The body member has an open-ended bore therethrough constituting a sight passageway. A pair of light transmitting quartz rods are positioned in the respective open ends of the bore to close them. One end of the debubbler unit functions as a fluid inlet conduit and a tubular neck portion extends from the bottom of the debubbler unit and is transversely connected to the open-ended bore of the body member intermediate its ends. A tubular fluid outlet tower has its bottom end transversely connected to the open-ended bore of the body member intermediate its ends.