Testing product

• US 4,090,926 A
• Filed: 03/15/1976
• Issued: 05/23/1978
• Est. Priority Date: 09/11/1974
• Status: Expired due to Term

• Current Assignee: Esa S.R.O. (Logisteed Limited)
• Original Assignee: Environmental Sciences Incorporated
• Inventors: Matson, Wayne R.
• Primary Examiner(s): Tung, T.
• Application Number:
  US05/666,664
• Time in Patent Office: 799 Days
• Field of Search: 204/1 T, 204/195 R, 204/ 195 H, 23/230 B, 23/230 R, 23/230 M, 260/438.5 R
• US Class Current: 205/792
• CPC Class Codes: G01N 27/42 Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte
• CPC Class Codes: G01N 27/48 using polarography, i.e. measuring changes in current under a slowly-varying voltage

Abstract

A system is disclosed for voltammetry such as anodic stripping voltammetry including a special electrode mounted to be fitted into a sample holder, stirring means operable through the electrode and an electrolytic potential source, optionally pulsed, capable of scanning the operating potential range which may for example, be a range between about -1 volt and 0 volt. Output recording means can be either an analog chart output or digitalized output. The system may be employed for a wide variety of test purposes generally relating to identifying and measuring heavy metals, one of which is detecting and measuring trace mineral components or trace elements in samples of human blood. When employed with blood samples the sample may first be prepared in the usual manner including digesting the sample but the presently preferred procedure comtemplate that the metals being tested are first displaced from blood complexing with a suitable ion such as Cr³⁺ or Ca²⁺ and the operating potential from about -800 millivolts to nearly 0 volt is scanned to read out the presence and quantity of metal such as lead, cadmium, copper and the like. An analysis of such metals can be run in as little as a minute. The ratio of electrode area to sample volume disclosed is 4cm² per 1.0 milliliter. A self contained test composition is disclosed.

Claims

1. A method of testing an organic sample for detection and measurement of trace quantities of at least one heavy metal comprising,

providing a matrix essentially free from said heavy metal and containing a measured quantity of at least one displacing metal ion-containing reagent adapted to displace the test metal from its organic chemical bonding and characterized by not plating out with said heavy metal at the electrolytic deposition potential of said heavy metal;

mixing with said matrix a measured quantity of the organic sample to be tested;

applying a cathodic electrolytic potential to said mixture to deposit said heavy metal on a test electrode,

thereafter releasing said heavy metal from said electrode by sweeping said electrode with a progressively varying anodic potential,

detecting and identifying said heavy metal by the release potential, and

measuring the quantities of said heavy metal by the electrolytic current at said release potential.

3. The method of claim 1, wherein said sample is an organic sample containing at least one heavy metal complexed therein.

2. A method of testing a sample for electrochemical detection and measurement of trace quantities of a heavy metal comprising,

providing an organic sample to be tested,

mixing with said sample a measured quantity of an electrolytic aqueous reagent containing at least one displacing metal ion adapted to displace said heavy metal from its organic chemical bonding within the organic sample, and characterized by not plating out with the heavy metal at the electrolytic deposition potential for said heavy metal,

thereafter applying a cathodic electrolytic potential to said reagent to deposit said heavy metal on a test electrode,

releasing said heavy metal from said electrode by sweeping said electrode with a progressively varying anodic potential including the anodic potential at which said heavy metal is electrolytically removed from said electrode,

detecting and identifying said heavy metal by identifying the release potential, and

measuring the quantity of said heavy metal by measuring the electrolytic current at said release potential.

4. The method of claim 2, wherein said heavy metal is lead and wherein said reagent includes at least one of the metal ions chromic ion and calcium ion.

5. The method of claim 2, wherein said sample is blood and wherein said heavy metal being detected and measured is lead.

6. A method of testing an organic sample for detection and measurement of trace quantities of at least one heavy metal selected from the group consisting of zinc, cadmium, lead, copper, bismuth, silver, gold and thallium comprising,

providing a matrix essentially free from said heavy metal being detected and measured and containing a measured quantity of at least one displacing metal ion-containing reagent adapted to displace said heavy metal from its organic chemical bonding and characterized by not plating out with said heavy metal at the electrolytic deposition potentials of said heavy metal,

mixing with said matrix a measured quantity of the organic sample to be tested;

applying a cathodic electrolytic potential to said mixture to deposit said heavy metal on a test electrode,

thereafter releasing said heavy metal from said electrode by sweeping said electrode with a progressively varying anodic potential,

detecting and identifying said heavy metal by the release potential corresponding to said heavy metal, and

measuring the quantities of said metal by the electrolytic current at said release potential.

7. A method of testing a sample for electrochemical detection and measurement of trace quantities of at least one heavy metal selected from the group consisting of zinc, cadmium, lead, copper, bismuth, silver, gold and thallium comprising,

providing a sample to be tested,

mixing with said sample a measured quantity of an electrolytic aqueous reagent containing at least one displacing metal ion adapted to displace from the sample said heavy metal, and characterized by not plating out with said heavy metal at the electrolytic deposition potential for said heavy metal,

thereafter applying a cathodic electrolytic potential to said reagent to deposit said heavy metal on a test electrode,

releasing said heavy metal from said electrode by sweeping said electrode with a progressively varying anodic potential including the anodic potential at which said heavy metal is electrolytically removed from said electrode,

detecting and identifying said heavy metal by identifying the release potential, and

measuring the quantity of said heavy metal by measuring the electrolytic current at said release potential.