A rapid, high sensitivity technique for measuring arsenic in skin phantoms using a portable x-ray tube and detector

Using a portable x-ray tube and silicon PiN diode detector, an improved approach to the measurement of arsenic in skin phantoms was demonstrated. Skin phantoms of 8 mm thickness were made from polyester resin, with arsenic concentrations ranging from 0 to 30 microg g(-1). The excitation of characteristic arsenic x-rays was performed with the x-ray tube and K(alpha) x-rays were used as an indicator of arsenic concentration. From repeated phantom measurements, an instrumental minimum detection limit of 0.446 +/- 0.006 microg g(-1) was found, using an acquisition time of 120 s (real time). This compares with previously reported approaches having instrumental minimum detection limits of 3.5 +/- 0.2 microg g(-1) (1800 s real time), 2.3 +/- 0.1 microg g(-1) (1000 s live time) and 0.40 +/- 0.06 microg g(-1) (1000 s live time).