Detection of Capsule Tampering by Near-Infrared Reflectance Analysis

CONCLUSION This paper has demonstrated that PbH, is not generated in organic media in conditions similar to those required in water. It has been proved that when lead is introduced in the form of a volatile organometallic compound, such as PbR4, the process that takes place is the volatilization of the PbR, itself and not the formation of PbH4 as might be expected. This volatilization is even more efficient, and therefore more economical, ifinstead of NaBH4, NaHCO, is used. The decomposition of the latter in situ in an acidic medium gives off C02 strongly and this, together with the carrier gas, carries the PbR4 to the silica tube of the atomizer. A new, fast, sensitive, and accurate procedure for determining volatile lead compounds in gasoline is proposed, which has the additional advantage that it is direct and does not require prior handling or alteration of the sample; it is sufficient to dissolve it in Me2S0. A procedure for independently determining volatile lead compounds is proposed and opens up new methods for introducing volatile samples in AAS. However, this method does not permit determination of the specific form of organometallic lead, but only the volatile lead compounds. Moderately volatile lead organometallics have not been addressed in this paper and may present some analytical difficulties.