Lead Profile Occupational Exposure, Blood
Method Description Describes how the test is performed and provides a method-specific reference
Zinc protoporphyrin is measured on the Helena ProtoFluor-Z hematofluorometer using a multi-channel front surface photofluorometer. When the sample is exposed to 415 nm light, zinc protoporphyrin (ZPP) is excited and emits light at 595 nm. A second lens/filter system collects, filters, and focuses the 595 nm light onto a photomultiplier tube (PMT). The PMT produces a current level in response to the light reaching it, which is proportional to the ZPP/heme ratio. During the 5 second reading, over 1,000 light-level readings are taken and averaged by the microcomputer and a value is displayed in mcmol ZPP/mol heme. The instrument can also convert this result to mcg ZPP/dL whole blood by changing the instrument mode. (Operatorâ€™s Manual: Helena ProtoFluor-Z 7/2006)
Lead in blood is determined by graphite furnace atomic absorption spectrometry. Samples are prediluted with a matrix modifier solution. The sample is then deposited in a depression on a carbon rod in an unclosed chamber. The furnace is electrically heated to a temperature sufficient to vaporize the lead in the sample. Light emitted from a hollow cathode lamp at 283.3 nm is absorbed by the vaporized atoms in the ground state. The concentration of lead in a sample is determined by comparing its measured emission signal with those obtained from a blank and calibration standards. Quantitative measurement is based on Beer's Law. (Parsons PJ, Slavin W: A rapid Zeeman graphite furnace atomic absorption spectrometric method for determination of lead in blood, Spectorchimica Acta 1993;48B[6/7]:925-939)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
See Individual Unit Codes
Performing Laboratory Location The location of the laboratory that performs the test