Separation and identification of DDT analogs in the presence of polychlorinated biphenyl compounds by two-dimensional thin-layer chromatography

Chemistry of PCBs and PBBs

“…The use of column chromatographic or chemical reaction procedures to separate PCBs from organochlorine pesticides increases the certainty of the gas chromatographic identification. Procedures readily available to the residue laboratory for confirming the identity of PCBs include: halogen specific gas chromatographic detectors (50), stability of the residue peak pattern after refluxing the extract with alcoholic alkali solution (10), perchlorination of the residue to the decachlorobiphenyl derivative (62,63), and thin-layer chromatography (64,65). Mass spectrometry is not readily available to many laboratories conducting analyses for PCBs nor would the expense justify regular use in monitoring programs.…”

About Some Specific Features of TLC in an Ultra-Small Volume S-Chamber and a Chamber with a Closed Sorption Layer

“…According to this prediction, the S min -chamber was recently implemented with a minimal distance d = 0.2 mm for PTLC-AF-V-UV plates (IMID, Krasnodar, Russia) and with d = 0.1 mm for Silica Gel F 254 plates (Merck, Germany) [3]. Let us note that in the literature on S-chambers, only the data for chambers with d = 0.5 mm [8], d = 1 mm [9,15] and more [10][11][12][13][14]16] have been published.…”

“…In this chamber the value d makes up only 0.1-0.2 mm, which is of principal significance, as shown by the authors [3]. In the articles and the monographs known to us, this value ranges between 0.5 mm [8], 1-1.5 mm [9][10][11][12][13][14][15] and 5 mm [16]. Despite the long-known simplicity of the design of S-chambers [2,9,10,12,15,[17][18][19][20], this type of chamber is in limited use nowadays.…”

Enhanced Photoactivated Luminescence of Selected Polychlorinated Biphenyl Congeners and Aroclor Mixtures

“…PCBs are known to be potent inducers of formation of enzymatic complexes like aryl hydrocarbohydrogenase (AHH) and ethoxyresorufin-o-deethylase (EROD), which lead to the toxic effects (4). It is seen that the toxic behavior of PCBs is structure dependent and is identical to the behavior of an extremely carcinogenic compound, 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (2,3,7,. Studies indicate that the toxicity of PCBs is related to their planarity; i.e., the more coplanar congeners (without ortho substitutents) are the most toxic ones.…”

“…High-resolution GC is accepted as the best available method for analysis of complex PCB mixtures (6). PCBs have also been analyzed using thin-layer chromatography (7,8). Further, room temperature fluorescence (RTF) (3), room temperature phosphorescence (RTP) (9,10), and low-temperature phosphorescence (LTP) (3) have also been used to detect PCBs.…”