Determination of the elvel of heavy metals pollution in drinking water (Qalqilya Region)

Supervisor: Dr.Raqi Shubietah      

Abstract :

Sampling & Methodology :

Samples of drinking water were collected from wells in Jenin  area& soil samples were collected from Azzoun;  two areas in north Palestine. Plastic containers with 30- ml capacity, were used to collect all samples. Containers had been soaking in hydrochloric acid 10% w/v concentration for 48 hrs before samples were collected, to prevent  loss  of   metal ions by being adsorbed  at containers surfaces.
Samples were collected , which is defines the wells from which samples were taken .
Five soils samples were  collected from different positions  in  Azzoun area , near a waste place .
Instruments: Atomic absorption spectrometer (AAS), is the instrument used in this project.  Its measurement is the absorbance of analyte which had been converted  to gaseous atoms(mostly in the ground state level of energy) by a flame or a furnace.
Three techniques are the most techniques used  recently:
1-flame atomic absorption spectrometry.
2-grafite furnace absorption spectrometry.
3-inductively coupled plasma- optical mass spectrometry (ICP-OMS).
Flame atomic absorption spectroscopy:
Its signal depends on the amount of light energy absorbed by samples, higher concentration of samples mean higher light absorption.
Unknown concentration of a  specific analyte can be measured by using a known concentration of the same analyte as standard.  Both analyte and standard should be measured at the same wavelength and same other conditions of the instrument. The concentration of standard  should be chosen to lie in the linear range of signal versus concentration. If the sample was out of the linear range, it may be diluted to lie within the linear range.
AAS requires light source, usually a  hollow cathode Lamp (HCL) or electrode less discharged lamp (EDL). Each element has its own specific lamp, few elements can be combined in a multi-element lamp.AAS also requires an atom source (atomizer) , a monochromator which  isolates the specific wavelength of light to be measured, a detector to detect and measure the light .

Sample is put directly into the graphite tube , solvents and major matrix components are removed from the sample by heating in series steps then atomize the remain sample. Light pass through the graphite tube which contains the sample. Gaseous atoms in the flame or furnace, can absorb only the wavelength that an excited atom of that metal will produce.