Rapid determination of molybdenum in ferromolybdenum and molybdenum additives, with oxine.

A rapid method is presented for the gravimetric determination of molybdenum (as the oxinate) in ferromolybdenum and molybdenum additives. The sample is fused with a mixed flux of sodium peroxide and sodium carbonate in a zirconium crucible for complete decomposition. Leaching the cooled fusion cake with water provides instantaneous separation of molybdenum as sodium molybdate from iron(III) and other hydrous oxides. After filtration, the molybdenum is precipitated with oxine after addition of EDTA and oxalate to obviate interference from other metal oxinates, and determined gravimetrically. The precision and accuracy are comparable to those of referee methods.

Study of radon daughter concentrations in Polk and Hillsborough counties.

The present study finds the average excess dose equivalent resulting from external gamma radiation on reclaimed land to be 17 mrem/yr (whole body); the highest excess is 166 mrem/yr, well below the NCRP limit that might be compared (500 mrem/yr). In contrast, the annual average excess exposure from radon-daughter inhalation on reclaimed land has been found to be 540 mrem/yr to the whole lung, more than twice that resulting from natural background in the study area and more than 5 times the national average dose equivalent reported in NCRP 45 (100 mrem/yr). Moreover, a significant number of individuals presently receive lung doses exceeding limits inferred from NCRP recommendations. These results indicate the need for corrective action to reduce radiation exposure of members of the general population whose exposure exceeds dose limiting recommendations and possibly to reduce radiation exposures well below these limits, thereby lowering risks even further.