Chemistry

Chemistry Science Fair Projects Testing for Lead in Everyday Materials



Tweet
Dawn Denmar's image for:
"Chemistry Science Fair Projects Testing for Lead in Everyday Materials"
Caption: 
Location: 
Image by: 
©  

There are several methods for testing for the presence of lead in everyday materials and some of these are listed below. 


Firstly, it is important to point out that lead can be dangerous to humans, when present in high quantities, and can also contaminate the food chain which directly affects humans too Lead is an essential component of many products, including batteries and glass, but manufacturing these products can lead to contaminated soil and water with high levels of lead. 


Some of the methods that are used in commercial laboratories to test for the presence of lead are complex but the following ways to test can be followed in the school environment.



* How to test for lead in everyday materials:


Commercial laboratories' tests for lead depend on the structure of the sample to be tested. Different tests are made on different samples,  for example separating out cadmium, sodium, mercury, zinc from the samples may indicate the presence of high or low levels of lead.



* Testing for lead in destructive sample:


For destructive sample like water and soil (aggregates,bitumen,concretes) we have to make some specific sample preparation to transform these sample into liquids that can be tested on the appropriate instruments.  This will all depend upon methodology and instruments present within the laboratory.


If we have an atomic absorption and inductively coupled spectrometry instruments, we have to do digestion preparation meaning adding sulfuric acid and nitric acid to dissolve all constituents and put them in microwave for at least 40 minute. when sample are cold  we transfer them in a test tube  and are anlyse and quantified. The purpose of this  test is to identify the principals elements like lead,sometime there is no lead in water or soil meaning insignificant value has been found (<0.2mg/l). it means no danger or harm.


* Testing for lead in non-destructive samples:



The main instrument used is  XRF (X ray fluorescence) which is very powerful and quick. It allows us to identify any element existing, for example sodium (Z=11). XRF machines are very expensive to purchase and to operate.

 

* Analysis of metal by wet chemistry:



Wet chemistry is utilized  for identifying and quantifying the elements in metals when optical emission spectroscopy and atomic absorption spectroscopy cannot be reliably performed on a sample.  Wet chemical analysis is also performed as a reference method when other classical analytical methods are inconclusive. This is performed for qualitative chemical measurements like colorimetry (changes in color), and other processes like titrimetry and gravimetry.



Conclusion:


There are many ways to trace the presence of lead, as it is largely  present in our life (blood,food,soil). The methods specified above are not exhaustive and can easily be transferred to the school environment.



Tweet
More about this author: Dawn Denmar

From Around the Web




ARTICLE SOURCES AND CITATIONS