The mass spectrometry of a number of 6-substituted coumarins was studied in the context of correlating fragmentation pathways and electronic charges of atoms performed by AM semiempirical method. The atomic charges of atoms are found to be good predictors of the fragmentation pathways.

The lead content of teeth or tooth-parts has been used as a biomarker of cumulative lead exposure in clinical, epidemiological, environmental, and archaeological studies. Through the application of laser ablation inductively coupled plasma mass spectrometry, a pilot study of the micrometer-scale distribution and quantification of lead was conducted for two human teeth obtained from an archeological burial site in Manhattan, New York, USA. Lead was highly localized within each tooth, with accumulation in circumpulpal dentine and cementum. The maximum localized lead content in circumpulpal dentine was remarkably high, almost 2000 μg g(-1), compared to the mean enamel and dentine content of about 5 μg g(-1). The maximum lead content in cementum was approximately 700 μg g(-1). The large quantity of cementum found in the teeth suggested that the subjects had hypercementosis (excess cementum formation) of the root, a condition reported to have been prevalent among African-American slave populations. The distribution of lead in these human teeth was remarkably similar to the distribution that we previously reported in the teeth of present-day lead-dosed goats. The data shown demonstrate the feasibility of using laser ablation inductively coupled plasma mass spectrometry to examine lead exposure in archaeological studies.

The design and performance of an easily constructed cell for microscale spectroelectrochemical analysis is described. A cation exchange polymer film, Nafion, was used as a salt bridge to provide ionic contact between a small sample well containing a coiled wire working electrode and separate, larger wells housing reference and auxiliary electrodes. The cell was evaluated using aqueous ferri/ferrocyanide as a test system and shown to be capable of relatively sensitive visible absorption measurements (path lengths on the order of millimeters) and reasonably rapid bulk electrolysis (~ 5 min) of samples in the 1 to 5 μL volume range. Minor alterations to the cell design are cited that could allow for analysis of sub-microliter volumes, rapid multi-sample analysis, and measurements in the ultraviolet spectral region.