Document DD3dgoY8n1MzM9B2a2qgpdagQ

Monsanto PROM iNAMC * LOC4 S. Tucker - R&D Laboratories - South Second Street ..St._ .Louis December 12, 1969 R. A. Baxter - Ruabon H. A. Vodden - Ruabon R. E. Keller - S. 2nd W. R. Richard - GO D. Danna - GO TO :R* A- Lldgett - Ruabon I agree with your feeling that there Is definitely a need for higher resolution columns for PCB analysis, especially when dealing with weathered PCB samples In which the original isomer distribution has been altered. I have recently investigated the feasibility of using support coated open tubular columns with electron capture detection to analyze for low levels of PCB's (5 X 10"9g injected). I obtained fairly good resolution (see attached chromatograms of 1242 and 1248) but ran Into several correctable problems. First, the sample Injection volume I used was much too large and it adversely affected both the column life and Its resolution. It appears that the.on column Injection of 5 uls of hexane washed the liquid phase, off the column seriously shortening the life of the column. The large solvent volume also seemed to cause some peak broadening. ^ These effects can probably be overcome.by using more concentrated solutions in conjunction with a sample Inlet splitter, i.e., 1 ul Injection with ~20/l split. This would, of course, reduce the sensitivity by a factor 20 - 100X. Currently, I am awaiting the arrival of 100' of 0.02" XE-60 S.C.O.T. column Which I have ordered. When the column Is delivered and I've had time to try the above suggestions, I will let you know. . I have not observed any decomposition of Aroclor during gas chromatography. " ' db Attach. ii j ; t f. E. S. Tucker IN IQ REV II ! ' DSW 152690 STLCOPCB4040034