Now that we discussed about the sources of lead, you might wonder if it is possible to detect the presence of lead in our homes. Lab analyses are expensive and time-consuming. However the handheld x-ray fluorescence (xrf) analyzer is the best substitute because we can take the instrument to the product, for instance for testing the soil. This battery operated, handheld x-ray fluorescence xrf analyzer is useful in detecting not only lead but also chlorine, cadmium, mercury, chromium, etc.
Uses of handheld x-ray fluorescence XRF analyzer
Presently handheld x-ray fluorescence xrf analyzer is used in western countries mainly by the manufacturers, sellers and importers to ensure complete safety of the product from hazardous substances. The manufacturers use handheld x-ray fluorescence (xrf) analyzer to detect toxins at three stages:
- examining the raw materials before manufacturing
- analyzing if the toxic elements are within permissible limits during the manufacturing process
- verifying that the finished products comply with the specification of the the consumer safety guidelines.
Soil testing Vs Lead-leaching crops
Studies also indicate lead levels in people’s blood correspond directly to the amount of lead in the soil where they live. There can be many reason for the amount of lead in the soil to be more than that occurs naturally. Industrial activities, pesticide use, lead paint and lead batteries are some of the reasons for high level of lead in soil. When lead-leaching crops are cultivated is highly toxic soil they will be contaminated. Some of the common source of lead is through Lead-leaching crops including herbs, leafy greens and root vegetables such as potatoes, radishes and carrots. Handheld x-ray fluorescence (xrf) analyzer, are being used to detect the level of lead in the soil. Anyone who cultivates vegetables be it kitchen garden, farmhouse or community farms they can approach organization that conduct soil test using handheld x-ray fluorescence (xrf) analyzer. Soil amendments can be made if the soil is found to be high in lead content.
Relevance of handheld x-ray fluorescence (XRF) analyzer in India
There is high vulnerability to lead exposure as lead is found in many of the commonly used items, Batteries, Crayons, polymers, toys, paints, etc. As many homes are relatively old and small scale industries are found near to residential areas, the soil needs to be checked before cultivation is done. Handheld x-ray fluorescence (xrf) analyzer can be used to screen a wide rand of products, plastic, paints, toys, electrical items, etc.
Lead exposure is a matter of serious concern as there are about 600,000 new cases of children developing intellectual disabilities and around 143,000 deaths every year. Campaign against lead hazards in India has been going on for decades, successfully resulting in the introduction of unleaded petrol and the paint manufacturers specifying whether lead is present in their products. Efforts are also on to reduce lead related occupational health hazards in India. However, it was the detection of lead in maggi that spread awareness regarding lead exposure.
How does a Handheld x-ray fluorescence xrf analyzers work
In a x-ray fluorescence (XRF), the electrons are displaced from their atomic orbital positions, whereby releasing energy which has the characteristic of the elements like lead, cadmium, etc. The XRF instrument detects and registers the release of energy. The energy released helps in categorizing the element. Here is the analysis of the working of machine in detail:
The analyzer triggers X-ray beam with enough energy to affect the electrons in the inner shells of the atoms. The x-ray beam is then discharged from the front of the handheld XRF analyzer. The x-ray beam comes in contact with the atoms in the sample by moving the electrons out of place from the inner orbital shells of the atom. This movement occurs as a result of the difference in energy between the x-ray beam emitted and the binding energy that holds electrons in their proper orbits; the displacement happens when the x-ray beam energy is higher than the binding energy of the electrons with which it interacts. Electrons have fixed positon at specific energies in an atom. In each element spacing between the orbital shells of an atom is unique to the atoms, so an atom of potassium (K) differs from the spacing between an atom of gold (Au), or silver (Ag), etc.
When electrons are displaced of their orbit, they leave behind vacant space, destabilising the atom. In order to correct, the instability created by the vacancies that the displaced electrons left behind, the atoms from higher orbits move down to a lower orbit where a vacancy exits. For instance, if an electron is shifted from the innermost shell of the atom, an electron from the upper shell can move down to fill the vacancy. This is fluorescence.
As electrons have higher binding energies the further they are away from the nucleus of the atom, an electron loses some energy when it drops from a higher electron shell to an electron shell closer to the nucleus. The amount of energy lost is equivalent to the difference in energy between the two electron shells, which is determined by the distance between them. The distance between the two orbital shells is unique to each element, as mentioned above. The energy lost helps in identifying the element from which it emanates, as the amount of energy lost in the fluorescence process is unique to each element. The individual fluorescent energies detected depends upon the elements that are present in the sample. In order to verify the amount of each element present, the proportion in which the individual energies appear can be calculated by the instrument.