DIRECT SOLID SAMPLING FOR ANALYSIS WITH INDUCTIVELY-COUPLED PLASMA USING A NOVEL ELECTRONIC SPARK SOURCE

A solid sampling accessory, using a spark discharge for introduction o f analyte material into an inductively coupled plasma (ICP) torch, has been developed. The device uses a novel electronic design which resul ts in a dramatic simplification of the hardware compared with previous ly described arrangements. A simple cell consisting of a tungsten elec trode adjacent to the sample in a flowing inert gas atmosphere complet es the unit as an extremely compact benchtop accessory. This device ha s been optimized for stable operation over a minimum of 12 min; relati ve standard deviations for signals over that period are typically less -than-or-equal-to 3%. Precisions of less-than-or-equal-to 4% were foun d for the determination of trace elements in National Institute of Sta ndards and Technology Standard Reference Materials with limits of dete ction in the single digit ppm range.