The simultaneous determination of 15 different wear metals in lubricating oil by inductively-coupled plasma-atomic emission spectrometry is described. An aerosol formed from a solution of the lubricating oil in 4-methyl-2-pentanone is injected into the axial channel of an inductiveiy-coupied plasma where the atomic spectra are excited. Detection limits range 0.0004 to 0.3 ppm for the elements studied. Low and high viscosity oils (nominally 1.9 X to 2.45 X m2/s, respectively) can be accommodated without biasing the analytical results. Approximately 1.5 min are required for completing the analyticai cycle for one sample. Relevant data on precision and accuracy are included.

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Emergency departments (EDs) are the primary venue for diagnosis and initiation of treatment of diabetic ketoacidosis (DKA). Typically managed in an intensive care unit (ICU), in many medical centers, limited ICU bed availability necessitates DKA-extended ED management until sufficient improvement for admission to a non-ICU bed. Although DKA treatment is well established, coordinating safe and effective extended care in a busy ED is complex. Recurrent problems in this high-risk transition of care led us to improvement efforts. We studied the impact of a standardizing ED DKA management in two phases: rollout of a DKA pathway in our computerized order entry system followed by audit and feedback. We evaluated adherence, clinical process, operational, and safety measures following these interventions. Adherence to the pathway was initially slow, improving significantly after audit and feedback. We observed mixed improvements in clinical processes, no changes in operational metrics (as expected), and reductions in variability for several measures. There were no deteriorations and improvements in measures of safety, and a reduction in the number of adverse event reports in the postimplementation periods.

Plasma ignition and sample introduction procedure 20 Sample preparation for lubricating oils 20 Dilution procedures and reference samples 20 Chemical oxidation procedure and reference samples 23 Analytical procedures 23 Analytical measurements 23 Wavelength profiles 23 CHAPTER III. DETERMINATION OF TRACE ELEMENTS IN PETROLEUM RELATED MATRICES 24 General Results 24 Wavelength scans 24 Detection limits 35 iii Analytical calibration curves 38 Wear Metals in Lubricating Oil 38 Metal Particles in Oil 44 Introduction 44 Wear metal particles in oil 47 Plasma emission-MIBK diluent vs. atomic absorption-acidified diluent 47 Chemical oxidation vs. dilution 53 Behavior of synthetic suspensions of iron particles in oil 55 Experimental equipment and sample preparation 56 Results and discussion 58 Loss of particles from suspension 58 Loss of particles in spray chamber Incomplete particle vaporization Summary Trace Metals in Fuel Oil CHAPTER IV. DETERMINATION OF TRACE ELEMENTS IN A CENTRIFUGED COAL LIQUEFACTION PRODUCT Wavelength profiles 79 Analytical results 89 Future Research 89 CHAPTER V. DETERMINATION OF TRACE ELEMENTS IN EDIBLE OILS 91 Experimental Conditions and Procedures 91 Samples, dilution procedures, and reference samples 91 Plasma torch placement 92 Other experimental conditions 92 Results and Discussion 94 Detection limits and analytical calibration curves 94 Wavelength profiles 94 Analysis of soybean oil samples 101 Analysis of commercial edible oils 105