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Lead Content in Toys

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.

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Lead Content in Toys

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  1. Lead Content in Toys Katrina Nowak Chemistry 4101 Fall 2008

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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)

  7. 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.

  8. 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: 0.02088 ± 0.00049 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, 01-01.

  9. 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.

  10. Instrumentation MGA-915 Atomic Absorption Spectrometer(5) • 12.4μg/L detection limit • 2nm Resolution • 41.3 LOQ • SD .00031 • 60-120s duration • 195-800nm Range • Use 217nm for measurements http://www.lumex.biz/product/mga915.shtml

  11. References • (1) http://www.atsdr.cdc.gov/tfacts13.html Accessed November 2008 • (2)16 C.F.R. 1301 • (3)http://www.alsglobal.com/Mineral/ALSContent.aspx?key=29#Limitations%20of%20XRF%20Spectroscopy Accessed November 2008 • (4) http://www.hc-sc.gc.ca/cps-spc/prod-test-essai/_method-chem-chim/c-02-eng.php Accessed November 2008 • (5) http://www.lumexint.com/product/mga915.shtml Accessed November 2008

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