Lead Content in Toys Katrina Nowak Chemistry 4101 Fall 2008

Sources of Lead A major source of lead found in toys comes from lead-based paints and dyes. Lead-based paints are used over paints with low lead concentrations due to lower cost. Difference in safety regulations in other countries where the toys are made also adds to the problem.

Hazards of Lead Paint Lead is especially dangerous to children still developing, it can damage the nervous system, cause hearing loss, stunt growth, and delay development.(1) Lead can cause kidney damage and affect every organ system in the body. It can also lead to increases in blood pressure.

The Problem 0.06% by weight (600ppm) lead content is the maximum allowed by the Consumer Product Safety Commision.(2) Every year toys are recalled due to excess lead content in paint. -The most common lead-based paint used is red lead, I would like to look into finding a way to accurately and efficiently determine the amount of lead used in paint for toys.

Detection Options Detection of lead based paints can be preformed by many methods. Some of the most common methods are Inductively coupled plasma (ICP), Atomic Absorption Spectrometry (AAS), GC-MS, and X- Ray Fluorescence (XRF). Each has there advantages and disadvantages, to determine the lead content in paint in ppm, I would like to use AAS.

AAS Advantages High sensitivity and selectivity. Relatively inexpensive and easy to use. Fewer matrix and other interference effects. Quick measurements. Measures over a wide spread of concentrations.(3)

Sample Preparation Scrape a small sample, 5-20mg, of paint off of the surface. Digest the paint sample in a disposable glass tube with a heating block using concentrated nitric acid and boiling water. Once it dries completely redissolve in HCl, and boiling water. Run sample through a filter, or centrifuge, to get rid of any undissolved paint chips. Dilute sample with DI water so that it is within the range of detection of the instrument. Analyze samples using AA Spectrometer.

Calibration Get the absorbance of at least 3 varied concentrations of a reference material such as NIST Standard Reference Material 2582, powdered "Lead Based Paint" (certified lead content: ± weight percent).(4) Using the known concentrations and absorbance, I would create a calibration curve to solve for an unknown absorbance. The linear regression of the calibration curve would later allow the determination of the concentration of lead in the paint sample. Jaiswal A., et al. Ind Med, 2006, 6,

Running the Sample First I would run a blank spectrum for HCl and Nitric acid. Next, I would run the prepared sample to determine its absorbance. The absorbance and calibration curve can tell us the concentration of lead present. The equation where: C = Concentration of lead measured in the test sample solution (µg/mL), Df = Dilution factor, Wt = Weight of the dried sample used (g) can be used to solve for the percent of lead present in the sample.

Instrumentation MGA-915 Atomic Absorption Spectrometer(5) 12.4μg/L detection limit 2nm Resolution 41.3 LOQ SD s duration nm Range Use 217nm for measurements

References (1) Accessed November 2008http:// (2)16 C.F.R (3) ey=29#Limitations%20of%20XRF%20Spectroscopy Accessed November 2008http:// ey=29#Limitations%20of%20XRF%20Spectroscopy (4) essai/_method-chem-chim/c-02-eng.php Accessed November 2008http:// essai/_method-chem-chim/c-02-eng.php (5) Accessed November 2008http://