Wear metal determination by plasma jet direct current arc spectrometry

Source identification of oil spills by pattern recognition analysis of natural elemental composition

“…The plasma concentration, therefore, reflects the myocardial concentration and may serve as a guide to drug dosage. Using this rationale, assays have been developed for the measurement of serum or plasma digitoxin (9,10). The range of interest is 5-50 ng/ml.…”

“…Various analytical methods have been used in the analysis of oils, among them: gas chromatography (4, 5); infrared, fluorescence, mass and plasma emission spectrometry (6)(7)(8)(9); atomic absorption (10); neutron activation analysis (11, 12), and various wet-chemical techniques (13). To our knowledge, however, only one large-scale study has been carried out on the effects of weathering on a wide variety of oils: the Neutron Activation Analysis (NAA) study of 20 crude and 20 residual fuel oils (Table I) weathered under 9 different conditions (Table II) done by Intel Rad Tech (then Gulf General Atomic) in 1970 (14).…”

Efficiencies of sample introduction systems for the transport of metallic particles in plasma emission and atomic absorption spectrometry

“…Although wear metal particles are not uniformly distributed in oil, they are generally determined by using techniques traditionally applicable to the determination of metals in homogeneous solutions. Atomic absorption spectrometry (AAS), rotating disk electrode atomic emission (RDEAE), inductively coupled plasma (ICP), and direct current plasma (DCP) techniques have been used for the determination of wear metals in used lubricating oils (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). Even though plasmas produce higher temperatures than flames and arcs, our previous work showed that analyses of oils containing particles larger than, ca., 3-10 pm, are, in general, not quantitative (3,5,7).…”