Correlation of levels of inflammation and inward particle penetration in human gingiva.
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Biomedical subjects
Publications and source records attributed to D H Fine.
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By use of a new, highly selective detection technique for N-nitroso compounds, which is sensitive to picogram quantities and which is based on the catalytic cleavage of the N-NO bond and the subsequent detection of the nitrosyl radical, dimethylnitrosamine has been found in concentrations of 0.02 to 0.96 part per billion in three out of five air samples from Baltimore, Maryland, and 0.014 to 0.051 part per billion in five out of six air samples from Belle, West Virginia. The sensitivity of the analytical procedures used was 1 part in 10(12). The presence of dimethylnitrosamine has been confirmed by using the new detector in conjunction with both a gas-liquid chromatograph and a high-performance liquid chromatograph. In addition, between one and three as yet unidentified N-nitroso compounds were detected in both cities. N-Nitroso compounds were not found in air samples from Philadelphia, Pennsylvania; Wilmington, Delaware; and Waltham, Massachusetts.
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Thermal energy analysis (TEA) has been combined with gas chromatography (GC). The new GC-TEA technique is highly specific to compounds which contain heat labile nitrosyl groups. Because of the specificity of the technique, full use may be made of the TEA sensitivity. Analysis by direct injection of solutions containing less than 1 ng/ml N-nitroso compound is demonstrated.
The theoretical basis for the thermal energy analyzer is discussed. Using the principles outlined, the feasibility of selectivity detecting mug/kg levels of volatile and non-volatile N-nitroso compounds is established.
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