Determination of halogenated hydrocarbons by combined use of neutron activation analysis and capillary gas chromatography with electron-capture detection

Results obtained by the two techniques are compared. Two standard mixtures, one containing, HCB, DDT, DDE and DDD and the other chloro-, dichloro- and bromocyme, were at a halogen concentration of about 20, 2 and 0.2 mg l^?1. The neutron activation method gave an average recovery of 4% (relative standard deviation, 12%) based on 24 measurements for chlorine. For bromine, the figures were 99% and 11%, respectively. Volatile chlorinated organics pose a particular problem because they may evaporate during analysis. Investigations with chloroform as model substance, indicate that when sealed ampoules are used, the average recovery is 84% (r.s.d., 6%).