Course-time recoveries, labeled

Figure 3. Time-course recovery of dermally applied [ C] labeled paraChion, carbaryl, and thiodicarb equivalents in percentage of dose in feces, urine, carcasses, and skin (surface and penetrated residues) after application. (Reproduced with permission from Ref. 9. Copyright 1984, Academic Press.)...

The results in Figures 1 and 5 show that chilling in the light alters the relative incorporation of label into the pigment-protein complexes known to comprise LHC 11. While the 31 kDa chill-induced polypeptide described earlier disappears with 1 h of recovery at non-chilling temperatures, the pattern of label incorporation does not return to control levels for 24 h. This time course more closely parallels the recovery seen in other parameters altered by chill stress. 

Perhaps the simplest of all applications of radioisotopes in chemical analysis is the use of a yield monitor . The element to be measured is labelled by the addition of a known amount of carrier-free radioisotope, in the same chemical form, to the sample. After chemical separation of the element, a comparison of the activity of the recovered material with the original activity gives the chemical yield. The method is used frequently to correct for the chemical losses of carrier separations in activation analysis and is, of course, a standard procedure for checking gravimetric analytical methods. Considerable amounts of time can be saved in certain gravimetric analyses if less than quantitative recovery is accepted and radiometric yield correction is used. 

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