Abstract-The purpose of this survey is to establish reference bulk elemental abundances for the eucrites and thereby provide the basis to test core formation models as well as partial melting, fractional crystallization and magma ocean theories for the eucrite parent body. In order to evaluate bulk elemental abundances for the eucrites, 296 peer-reviewed articles, monographs, theses or books and 143 abstracts dating from 1938 to 1997 were surveyed. Of the 10 1 eucrites having at least one set of elemental abundance analyses reported in the literature, 20 were selected for in-depth examination. The selection criteria of our sample were based on the total number of analyses available for a given eucrite and the total number of elements for which data exist. The mean bulk elemental abundance, la standard deviation, and the percent deviation were calculated for each element in a given eucrite. In order to evaluate the quality of the mean abundances, the elements were then grouped according to availability of data and percent deviations. Possible reasons for the different deviations in the different groups are briefly discussed. From the major element abundances, the normative (CIPW) composition, the molar compositions of pyroxene, olivine and plagioclase, and the bulk densities were calculated and compared to petrographic observations. The calculated norms for the noncumulates agree well with the observations while the norms for the cumulates do not. Possible reasons for this are discussed. Unfortunately, analyses of many elements are poorly represented in the literature and many bulk analyses suffer from unacceptable levels of uncertainty. Therefore, future work requires bulk elemental analyses for some of the more poorly characterized elements in eucrites, especially those of key elements used for planetary modeling.

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Identification of the anions in inorganic explosives and their post-blast residues using ion chromatography (IC) and/or capillary electrophoresis (CE) is well established. However, IC and CE instrumentation are not as common in forensic science laboratories. Furthermore, coupling IC and CE to a mass spectrometer can be challenging as volatile buffers are required or ion suppressors must be used. Porous Graphitic Carbon (PGC) is a relatively new stationary phase type that is available for High Performance Liquid Chromatography (HPLC). PGC is known for its high retention of polar species and separation of anions using PGC has been demonstrated. In this work, a PGC (2.1 Â 100 mm) column was coupled to an electrospray ionization mass spectrometer (ESI-MS) for the analysis and detection of anions. Several parameters of the method were optimized including ion source temperature (550 C), MS cone voltage (75 V), injection volume (1 mL), solvent composition (1% formic acid in water), and column temperature (80 C). This resulted in a method that separated 6 anions Cl À , NO 3, and dicyandiamide (DCDA) in less than 5 min. Several low explosive powders were analyzed intact and after burning. Finally, the post-blast residues of two black powder substitutes were extracted from pipe bomb container fragments and analyzed using this technique.