An evaluation of fused silica capillary columns for the screening of basic drugs in postmortem blood: qualitative and quantitative analysis

Fused silica capillary columns (Durabond) have been evaluated for the screening of more than 100 basic drugs in postmortem blood samples. The combination of these columns, nitrogen-phosphorus detectors, and SKF-525A (internal standard) allows for the simultaneous screening and quantitation of several basic drugs such as amphetamines, amitriptyline, and codeine. Approximately 2000 blood samples have been analyzed by this procedure. The use of capillary columns results in excellent baseline stability and this, together with an autosampler and data system, enables unattended overnight operation. "Double peaking" associated with splitless injection can be a problem as can sensitivity for some of the polar drugs; however, with the extraction procedure described and the equipment used, the screening of blood for basic drugs is improved when compared with packed column technology.     

Migration,rank-size distribution,and economic development: The case of Mexico

This is an examination of whether city size is truly an independent variable when the relationships between city size and certain economic and social phenomena are considered. A new hypothesis is presented that postulates that relative or systemic city size is an independent variable that affects urban growth patterns through varying, non-optimum migration flows. The hypothesis is tested using official Mexican data for the period 1960 to 1970.