A SIMPLE PREPARATION METHOD OF THIN-LAYER STANDARD SAMPLES WITH ACTIVATED CARBON FOR THE MULTIELEMENT DETERMINATION OF AIRBORNE PARTICULATEMATTER BY X-RAY SPECTROMETRY

Thin-layer standard samples for the X-ray fluorescence (XRF) analysis of airborne particulate matter have been conveniently prepared by impr egnating activated-carbon powder with standard solutions of the elemen ts of interest and by drying it. Different amounts of standard solutio ns of the elements of 1.00 mg ml(-1) each and a 0.01% surfactant (Twee n 85) solution of 1.5 ml are added to a fine powder of activated carbo n of 5-10 mg on a hydrophilized poly(tetrafluoroethylene) membrane fil ter. The suspension of carbon is dispersed by blowing air from a pump for 2-3 min without bubbling and dried by IR irradiation for 10 min wi thout filtration. This filter with carbon is impregnated with a 0.02% polycarbonate dichloromethane solution of 0.3 ml, followed by air-dryi ng. Inductively coupled plasma atomic emission spectrometry of digesta tes from the prepared samples gave good recoveries of all the measured elements. The XRF intensities of the samples prepared repeatedly had reasonable reproducibilities. Calibration graphs with good linear rela tionships were constructed for 21 elements in the range of 0-50 mu g. The standard samples prepared were successfully used for the multi-ele ment XRF determination of airborne particulate matter, in good agreeme nt with the results of instrumental neutron activation analysis.