Project Identifier: LLNL-91-109
Project Title:
Ultratrace Hair Analysis
Principle Investigator:
Dr. Brian D. Andresen
Project started in: 1991
Project Funding Information:
Project received funding in Fiscal Year 1995.
Project used human subjects in Fiscal Year 1995.
Funding Sources:
Project does not involve use of multiple protocols/subprojects.
IRB Review:
Type of Review: Full Board
Most Recent Approval: March 22, 1995
IRB Approval Number: 91-109
Number of Human Subjects in the Last Reporting Period for this Project: 15
(Reporting periods vary.)
Type of Human Subjects Involvement:
Objective:
Hair can be a biological sample that reveals chemical exposures in humans. Incidental inhalation and ingestion of particles over extended periods of time may result in the formation of a diagnostic chemical fingerprint in hair samples. Methods will be explored to ascertain routine whether chemical exposures in the work environment can be revealed through ultratrace analysis of human hair samples.
Methodologies:
Human hair from individuals known to have been exposed to chemicals in the workplace will be analyzed. New analytical methods will be developed to assay for ultralow levels of certain organics (e.g., high explosives) and specific elements (e.g., actinides).
The focus of the hair analysis program centers first on reviewing the literature concerning the extraction of target analytes in laboratory-fortified hair samples. Several approaches will be reviewed in detail, for example, enzymatic digestion, organic solvent extractions, and mild acidic extractions. Depending on the harshness of the extraction, solid phase extraction (SPE) may be proposed as a partial method to clean up the extracts. Every extraction technique will be evaluated on its efficiency and ease of use. The work also includes the development of a laboratory protocol for organic extracts of hair that will either pre-concentrate the sample prior to analysis or evaporate the sample to dryness and then derivatize the isolated compounds and elements. It will be proposed to analyze each sample utilizing gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma mass spectrometry (ICP-MS). We will recommend equipment that is readily available to most analytical chemistry laboratories.
The use of matrix assisted laser desoption and ionization (MALDI) mass spectrometry will be evaluated for sectional hair analysis. Because hair grows at approximately 1 cm/month, it may be used to detect a history of chemical exposures. We plan to review the application of MALDI-MS for hair analysis of HE and actinide incorporation. MALDI-MS will enable us to precisely focus laser power on a selected portion of a hair strand utilizing a miniaturized video camera with newly designed laser optics to monitor the ionization points on the hair shaft. The ions created should allow an ion trap mass spectrometer (with MS/MS option) to detect target species. We will consider in our studies the level of concentration of chemicals in the hair and at what level the target species must be present in order to be seen with MALDI-MS. Most of the preliminary work will be performed with laboratory-fortified hair samples.
Ionizing Radiation:
No radiation experiments are anticipated in these studies. Only hair samples from individuals who work with radioactive materials will be utilized in these studies. No human experiments are anticipated.
Involvement of Human Subjects:
1. Hair samples from selected volunteers will be obtained for these studies. Typically hair is obtained during routine hair cuts at the local barber shops. The hair samples are placed in suitable containers and collected for analysis.
2. There is very little risk of injury in obtaining hair samples. The information obtained following the analysis is kept confidential and only available to selected researchers as coded data. No names are associated with the analytical chemistry findings.