Glass capillary columns coating

Culea et al. reported a quantitative GC-MS analysis of procaine and some neurotransmitters in rat brain tissue [94], Procaine was extracted fi om brain homogenates by the ultrasonication method of Sundlof et al. [95], and was determined in its underivatized form on a 24 m glass capillary column coated with Silar IOC (temperature programmed from 120°C to 225°C at 12°C/min with pyrene as the internal standard). It was found necessary to wash the injector liner and the GC-MS interface stainless steel tubing with 1 1 0.1 M KOH-methanol so that the interface tubing could be coated with a film of OV-17 (from acetone solution), and to condition the apparatus by injecting bis-(trimethylsilyl)-acetamide and triethylamine. 

Chromatographic Resolution. To optimize column-coating conditions and operating parameters glass capillary columns coated with various silicone-based stationary phases were tested with difficult-to-separate groups of PAH standards and Complex samples. The SE5 -coated columns performed excellently with respect to separation efficiency, column bleed and long-term stability. Other observers have had similar results with this... 

Analytical Instrumentation A Hewlett Packard model 5880-A series gas chromatograph equipped with flame ionization detection (FID) was fitted with an 18 m x 0.25 mm id glass capillary column coated with OV-101. Reaction mixtures and standards were injected through a stainless steel injector splitter with a split ratio of 100 1. The column oven was linearly programmed from 90 to 200°C at 2 or 5°/min. The injector and detector temperatures were... 

A DuPont model 21-492B GC/MS with an Incos data system was used to confirm the presence of thiazolidine and nitrosated thiazolidine. A 30 m x 0.24 mm id glass capillary column coated with SP-2250 was used for GC/MS analyses with a 30 1 split ratio (with the larger fraction vented to atmosphere through a charcoal trap). Electron impact ionization was used at 70 eV. The data system generated total ion current chromatograms and recorded mass spectra. 

The purity of the acetic anhydride is important (repeated distillation in an all-glass apparatus is recommended) as it may contain impurities that interfere with the peaks of the PCP derivatives in the chromatogram. An identical procedure was also used by Krijgsman and Van de Kamp [5], but the GC analysis was carried out in a glass capillary column coated with SE-30. Using the ECD, the detection limit of PCP acetate was 1 pg. The recovery of the extraction—acetylation step was 80—100%. An example of the analysis is shown in Fig. 5.1. 

Figure 6. Separation of various compounds on a 20 m X 0.25 mm glass capillary column coated with diethyl-4,4 -azoxydicinnamate.

Capillary gas chromatography of cocaine has so far been scarcely done. Christophersen and Rasmussen analyzed a number of narcotic drugs, i.a. cocaine, on a glass capillary column coated with SE-30 using cold on-column injection (50°C). The oven temperature was programmed... 

The major breakthrough in the GC enantiomer separation has been the work of Bayer and associates [23,76], who synthesized a silicone-based chiral phase, stable up to 240°C. As shown in Fig. 3.14, a racemic mixture of 19 protein amino acids can be separated [23] on a glass capillary column coated with Chirasil-Val, a chiral polysiloxane phase. The phase was synthesized through coupling L-valine-tert-butylamide to a copolymer of dimethylsiloxane and carboxyalkylmethylsiloxane. 

LtPSKY, S. R. Duffy, M. L. 1986a. High temperature gas chromatography the development of new aluminum clad flexible fused silica glass capillary columns coated with thermostable nonpolar phases Part 1. Journal of High Resolution Chromatography, 9, 376-382. 

Pentachlorophenol Glass capillary column coated with SE54 (20 ml/min, 10 1) GC-ECD" derivatization Grob and Neukom (1984)... 

Gas-chromatography coupled to mass spectrometry (G.C.-M.S.) was carried out on Rexco and Kuwait branched/cyclic fractions with a Pye IOU chromatograph (WCOT glass-capillary column coated with OV-1) on a Varian MAT hh spectrometer (with SS kk computer) at 70 eV ionization voltage. For Turkish Montan wax and asphaltite, G.C.-M.S. were run with the eutectic packed column on an MS 50 spectrometer. Field-desorption (F.D.) M.S. for Kuwait and Rexco samples were recorded on a Varian CH5D spectrometer (calibrated with perfluorkerosene) linked to a Varian Spectro-system 100 data output. 

Pyrex glass capillary column coated with Carbowax 20-M. The column was held at 50 C for 30 minutes after Injection and then temperature programmed at l°/mlnute to 170°C and held at this... 

In a recent work, Buckholz et al (21), the traps containing adsorbed volatiles were inserted directly into the modified injection port of a Varian 2700 gas chromatograph (GC) for analysis. A 400 ft. by 0.032 inch glass capillary column coated with SE-30 was used. The column was temperature programmed from 50 C to ISO C at 2 /min. 

Franken, J. J., Rutten, G. A. F. M., and Rijks, J. A., 1976, Preparation of glass capillary columns coated with polar phase for high-temperature gas chromatography, I. Study of roughening of the glass surface, J. Chromatogr., 126 132. 

Glass capillary column coated with methyl silicone, carbowax, 5%-phenyl-methylsiloxane are usually employed for the separation. Column temperature programming can be preliminary set by using medium ramping time of each step of increments, if the components are eluted unresolved or too far apart, the programme can be optimised. The maximum temperature for each type of column has to be carefully checked. 

Most of the reported applications of this technique involve the direct resolution of derivatised enantiomers on chiral stationary phases. The earliest successful resolution of yV-trifluoroacetyl amino acid esters on glass capillary columns coated with N-trifluoroacetyl-5-isoleucine lauryl ester (2) was effected in 1966. Superior stationary phases developed quickly, such as (3), in which the additional amide bond may interact via hydrogen bonding. These chiral supports work well for the separation of A -perfluoracylated derivatives of a given amino acid. However, their low thermal stability (190 C maximum) and appreciable volatility have inhibited their use for the simultaneous... 

Analysis of Reagent Purity GC at 210 °C on a glass capillary column coated with OV-17 TLC on silica (hexanes, R(... 

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