Determination of lead in biological and related material by atomic absorption spectrophotometry.
Yeager-DW; Cholak-J; Henderson-EW
Environ Sci Technol 1971 Oct; 5(10):1020-1022
A process using atomic absorption spectrophotometry (AAS) was developed for determining trace quantities of lead (7439921) in biological materials. Samples were ashed at 500 degrees-C, placed in a 50 milliliter (ml) flask, and drops of phenol-red indicator and 5ml of ammonium-citrate buffer were added. Ammonium-hydroxide was then added by drops until a red color was obtained. A solution of 1ml of 10 percent potassium-cyanide, 1ml ammonium-pyrrolidine- dithiocarbamate (APDC) reagent, and 4ml 4-methyl-2-pentanone (MIBK) were added, and the flask was vigorously shaken for 30 seconds. Distilled water was added to bring the MIBK layer up to the neck of the flask, which was inverted several times and let stand. The aqueous saturated MIBK was aspirated to establish the base line and then the MIBK layer of the sample was aspirated into the atomic absorption spectrophotometer. Samples of blood and urine to which known amounts of lead had been added were then analyzed. Results of the dithizone colorimetric procedure and the AAS method were compared on analysis of lead in 213 samples of blood, urine, tissue, feces, food, and bone. Of known lead samples added to 5 grams of blood, an average of 99.8 percent recovery was found. Lead recovery from urine samples averaged 98.8 percent. Results obtained with the colorimetric and AAS procedures differed by approximately 2.0 percent. Except for tissue analysis, results of the two methods were essentially the same. The author recommends alternate procedures for analyzing materials containing interfering substances. The AAS method is recommended for the determination of lead in the range of 05 to 20 micrograms of lead per sample, although it has been used to analyze samples containing up to 100 micrograms of lead.
NIOSH-Publication; NIOSH-Grant; Trace-analysis; Urinalysis; Colorimetry; Analytical-methods; Chelates; Laboratory-testing; Quantitative-analysis; Blood-analysis; Lead-absorption
Environmental Health Kettering Laboratory College of Medicine Cincinnati, Ohio 45219
Environmental Science and Technology
University of Cincinnati, Cincinnati, Ohio