SummaryThis paper describes an evaluation of the chromatographic performance of columns coated with amorphous cyclodextrin (CD) derivatives, in particular 2,3,6-tripentyl-P-CD (2,3,6-TriPe-P-CD), 2,6-dipentyl-3-methyl-P-CD (2,6-DiPe-3-Me-P-CD), and 2,6-dimethyl-3-pentyl-fl-CD (2,6-DiMe-3-Pe-P-CD), all diluted in polysiloxane (OV-1701 or OV-1701 -OH), for the separation of the enantiomers of volatile compounds. 2,6-DiMe-3-Pe-P-CD in OV-1701 offers Performance comparable with (or better than) that of the other two CDs, and without their drawbacks (inconsistency of results, as described previously).This article compares the separating ability of 2,6-DiMe-3-Pe-P-CD and 2,3,6-TriMe-P-CD, and describes the influence of the CD derivative to polysiloxane ratio, the minimum operating temperatures of the columns, and the reproducibility and consistency of performance of columns coated with the former CD derivative diluted in polysiloxane.

SummaryThe chromatographic separation of racemic mixtures of volatile compounds by 2,3,6-trimethyl-a-, fl-and y-cyclodextrins is discussed. Columns were prepared by mixing the derivatized cyclodextrin with OV-1701 or hydroxy-terminated OV-1701 (OV-1701-OH) following Schurig's method [l]. About 130 racemates with widely differing structures were used to test the performances of 2,3,6-pemethylated-a, p-and, y-cyclodextrins mixed with the polysiloxane polymers in different ratios.The influence of the different types of cyclodextrin on racemate separation is shown, and some phenomena which might be helpful in the elucidation of the chromatographic behavior involved are also described.The influence both of the percentage of cyclodextrin in the polysiloxane, and of the operating conditions (carrier gas, flow rate, and temperature) in the separation of flavor and fragrance racemates is also evaluated.

Short Communicationstrimethylsilylbromide derivatization was checked for Et-18-0Me and Thio-ALP using derivatized Et-16-OMe a s internal standard. From the linearity of each curve (range 10-30 ng ALP) it was apparent that both were converted to the same extent.This report focuses on the derivatization of ether phospholipids with trimethylsilyl bromide and the structural elucidation of the resulting derivatives. 1 -0ctadecyl-2-0-methyl-DL-bromopropane (Et-18-Br), 1-bromohexadccane (H-Br), l-hexadecylthio-2methoxymethyl-m,-bromopropane (Thio-AL-Br), and l-hexadecyl-2-0-methyl-~r,-bromopropane (Et-16-Br) are the derivatives of the anticancer drugs Et-18-OMe. HPC, and Thio-ALP and the proposed internal standard Et-16-OMe. The procedure facilitates further development of a quantitative analysis of ALPS by capillary gas chromatography.

The gas chromatographic performance of differently derivatized a-, p-, and y-cyclodextrins in the separation of racemic mixtures of volatile is investigated. The performances of 2,3,6-permethylated a-, p-, and y-cyclodextrins and 2,6-dimethyl-3-trifluoro-acetyl a-, p-, and y-cyclodextrins mixed with different ratios of OV-1701 or OV-1701-OH terminated were tested with racemates with widely differing structures. The influence of the percentage of cyclodextrins in polysiloxane, of film thickness of the stationary phase, of the length of the column, of column conditioning, and of the operating temperatures in the separations of different racemates has been evaluated.

SummaryAs a continuation of previous studies on the use of cyclodextrin derivatives (CD) for the separation of volatile compounds by capillary GC, the influence of diluting phases other than OV-1701 or OV-1701 -OH has been investigated. 2,6-Di-O-methyl-3-O-pentyl-P-cyclodextrin(2,6-DiMe-3-Pe-P-CD) was taken as the reference CD derivative, because of the large number of volatile racemates it is able to separate; OV-1701 or OV-1701-OH was chosen as the reference diluting phase.The performance of a column coated with a 0.15 ym film of 10 YO 2,6-DiMe-3-Pe-P-CD in OV-1701 was compared with that of analogous columns coated with films of the same thickness containing the same percentage of the CD derivative diluted with stationary phases of different polarity, be. . Resolution values and separation factors of thirty racemates were used to evaluate the effect of different diluting phases on column performance.