Optimum experimental factors were determined for the analytical determination of Al, Cd, Fe, Pb, and Zn by ICP atomic emission spectrometry. Based on systematically determined factor levels, working conditions were found that gave similar, and sometimes better results compared with the hitherto used levels of factors. All measurements were performed with a sampling time of 150 ms as often used in routine analysis in the laboratory. This optimization resulted in a reduced outer plasma gas flow from 15 L/min argon to 12 L/min without any relevant changes of the achievable detection limits. A serious problem was that only one analytical line of Al could be used. A comparison with the lower limit of application (comparable with the detection limit) from German directive DIN 38406, part 22 ([1]), showed that the detection limits of Al and Fe are superior, whereas for Cd there was only little improvement. The detection limits of Zn and especially Pb are always higher than the lower range of application under these conditions. Therefore, the use of two device-parameter sets for hard and soft lines, respectively, is strongly suggested. Maps with the observed signal-to-noise-ratios were systematically acquired for each element analyzed in connection with different strategies for optimum search. mon compromise condition (combined analysis) and the limits of quantification demanded in the German directive DIN 38406, part 22 [1]. Only four, but the most important, experimental factors were changed, the other experimental factors were always kept constant (Tables 1 and 2).

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The continued social and cultural value of sustaining America's history of segregation by maintaining what could be considered atavistic, race-assigned, public and private colleges remains an open axiological question in post-modern American society. With the loss of the traditional roles of these institutions as necessities for the education of marginalized African-American populations, the future role and identity of Historically Black Colleges and Universities (HBCUs) has been called into question beginning in the last quarter of the 20th and continuing into the 21st century. However, questions of race identity remain highly motivating socio-cultural catalysts for discourse in the first quarter of the 21st century. The following discussion considers the ways in which Historically Black Institutions produced scholars and cultural critics who have offered significant challenges to the status quo of American exceptionalist discourse and how museums at HBCUs have helped shape the foundational concerns of a 21st century re-imagining of American identity and shared values.

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