A new fast and standardless method for direct determination of metals associated with particulate matter in air: avoiding errors in the determination of Pb in an urban environment.
We describe a new method and the relevant instrumentation necessary for its implementation in the analysis of metals associated with particulate matter in air. The procedure can be divided into two steps: in the first step the sample is accumulated in a device through electrostatic precipitation whose center is a graphite tube; in the second step the graphite tube itself is used as an atomization device for the determination of the metals present in the sample through the electrothermal atomic absorption technique. The method is simple, fast, accurate, and inexpensive. Moreover, if the experimental conditions are well chosen, there is no need for calibration, which is very convenient in the case of samples such as particulate matter in the air. The elements that can be determined with the present apparatus are Hg, Cd, Tl, Ag, Mg, and Mn. These are highly or medium volatile because the materials used cannot reach very high temperatures for long periods. The experiments are confined to air, but other gases, in which a corona discharge is possible, would give the same results. With the method proposed, it was possible to show that the official method for Pb determination in the urban environment of Bologna presents a negative systematic error of about 25%.
Torsi
G
G
Reschiglian
P
P
Locatelli
C
C
Melucci
D
D
D007854:Lead / Q000032:analysis*; D013054:Spectrophotometry, Atomic / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D055672:Static Electricity; D014504:Urban Health
D007854:Lead