Blood testing method

• US 5,427,953 A
• Filed: 11/08/1993
• Issued: 06/27/1995
• Est. Priority Date: 11/08/1993
• Status: Expired due to Fees

• Current Assignee: VHS of Michigan, Inc. (Tenet Healthcare Corporation)
• Original Assignee: Detroit Medical Center (Tenet Healthcare Corporation)
• Inventors: Yee, Hugh Y.
• Primary Examiner(s): Czaja, Donald E.
• Assistant Examiner(s): TRAN, LIEN THUY
• Application Number:
  US08/148,982
• Time in Patent Office: 596 Days
• Field of Search: 422/61, 422/68.1, 422/69, 422/73, 436/73, 436/74, 436/77, 436/164, 436/171, 436/177, 436/178, 436/182, 436/166
• US Class Current: 436/74
• CPC Class Codes: G01N 33/491 by separating the blood components G01N15/05 takes precedence

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. The method allows easy, economical and accurate testing of blood samples using standard analytical chemical measurement of trace elements such as lead.

Claims

1. A method for determining the amount of heavy metal trace elements in a blood sample, comprising the steps of:

spotting a blood sample on a filter collection paper;

drying the spotted blood sample on the collection paper;

removing a predefined area containing the dried blood sample from the collection paper;

placing the predefined area containing the dried blood sample into a solution of dilute aqueous acid reagent containing a surfactant wetting agent;

mixing the solution and the dried blood sample;

allowing the mixture of the dried blood sample and the solution to stand for a first predetermined time;

centrifuging the mixture for a second predetermined time;

removing a clear supernatant liquid from the mixture; and

testing the clear supernatant liquid for traces of heavy metal elements.

2. The method of claim 1, wherein the step of mixing is by vortexing.

3. The method of claim 1, wherein the step of testing the clear supernatant for heavy metal trace elements is by an atomic absorption spectrometer.

4. A method for determining the amount of lead trace elements in a blood sample, comprising the steps of:

collecting a whole blood sample by means of a finger or earlobe prick;

spotting the collected blood sample on a filter collection paper;

drying the spotted blood sample on the filter collection paper;

punching out segments equaling approximately one-half inch diameter of the collection paper containing the dried blood sample;

placing the segments of the collection paper containing the dried blood sample into a test tube;

adding into the test tube approximately a 1.0 milliliter solution containing 5 percent volume per volume of nitric acid and 0.75 percent volume per volume of a non-ionic polar surfactant;

mixing the solution with the segments of the collection paper containing the dried blood sample;

allowing the mixture of the dried blood sample and the solution to stand for approximately 15 minutes;

centrifuging the mixture in the test tube for approximately 5 minutes;

removing a clear supernatant from the test tube; and

testing the clear supernatant liquid for traces of lead with an atomic absorption spectrometer.