Other

General Electric Company

United States Drug Testing Laboratories, Inc.

Douglas E Lewis

Andrew Lee Trimmer

John Malott Cottrill

Christine M Moore

Electrochemical machining of parts employs electric or voltage pulses in which current flows in a first direction and a second direction opposite from the first direction. The cathodic/anodic pulses switch between bulk machining and oxide removal pushing bulk material removal into a homogenous regime to obtain a smooth surface finish and appropriate form control during the electrochemical machining process compared to electrochemical machining employing an electric or voltage potential in which current flows in only one direction.

Electrochemical machining employing electrical voltage pulses to drive reduction and oxidation reactions

A improved method for preparing a concentrated meconium extract containing basic and acid-neutral target analytes present in a meconium sample suspected of containing the target analytes is provided. The meconium sample is extracted with a mixed solvent of acetonitrile and a volatile organic acid and the resulting organic phase is separated. The organic phase is diluted with water to provide an organic solution which is passed through a mixed mode solid phase extraction column having strong cation exchange and hydrophobic functionality. Acid-neutral and basic target analytes are sequentially eluted from the column and the eluates are combined to form a combined extract. The combined extract is evaporated to dryness and reconstituted in buffer to provide a clean concentrated neonatal meconium extract for use in qualitative and quantitative analyses.

Meconium assay procedure

New and improved methods for collecting neonatal meconium samples, preparing meconium specimens for testing and for chemically analyzing neonatal meconium samples to determine their chemical composition are provided. A novel extraction method is employed in accordance with the invention to provide a non-aqueous, concentrated 'cocktail' meconium extract containing substantially all of many possible target analytes in a single extraction step. Preliminary screening by fluorescence polarization immunoassay methods may be performed on the cocktail extract to qualitatively determine the presence of the target analytes in the meconium sample. If a positive preliminary result is obtained, new and improved quantitative GC/MS confirmatory procedures are provided by this invention to unequivocally identify and quantitate the amount of target analyte present in the sample in terms of nanograms of analyte per gram of meconium tested.

Forensically-acceptable determinations of gestational fetal exposure to

Methods for collecting neonatal meconium samples, preparing meconium specimens for testing and for chemically analyzing neonatal meconium samples to determine their chemical composition are provided. A novel extraction method is employed in accordance with the invention to provide a non-aqueous, concentrated 'cocktail' meconium extract containing substantially all of many possible target analytes in a single extraction step. Preliminary screening by fluorescence polarization immunoassay methods may be performed on the cocktail extract to qualitatively determine the presence of the target analytes in the meconium sample. If a positive preliminary result is obtained, new and improved quantitative GC/MS confirmatory procedures are provided by this invention to unequivocally identify and quantitate the amount of target analyte present in the sample in terms of nanograms of analyte per gram of meconium tested.

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Chicago, IL, United States of America

Douglas E Lewis