Capillary film thickness

SPME has been utilized for deterrnination of pollutants in aqueous solution by the adsorption of analyte onto stationary-phase coated fused-siUca fibers, followed by thermal desorption in the injection system of a capillary gas chromatograph (34). EuU automation can be achieved using an autosampler. Eiber coated with 7- and 100-p.m film thickness and a nitrogen—phosphoms flame thermionic detector were used to evaluate the adsorption and desorption of four j -triazines. The gc peaks resulting from desorption of fibers were shown to be comparable to those obtained using manual injection. 

Fig. 10. Reverse-roU, metered film thickness on the appHcator roU divided by gap, tjG, as a function of the ratio of the metering roU speed, U, to apphcator roU speed, U, for various capillary numbers. (—) represents theoretical values ( ) experimental ones and (------) is the lubrication model (11).

Duranglas glass capillary column (30 m X 0.23 mm i.d.) coated with OV-215 (0.23 p,m film thickness)... 

Figure 10.3 Gas cliromatograms of a cold-pressed lemon oil obtained (a) with an SE-52 column in the stand-by position and (b) with the same column showing the five heart-cuts (c) shows the GC-GC chiral chromatogram of the ti ansfeired components. The asterisks in (b) indicate electric spikes coming from the valve switcliing. The conditions were as follows SE-52 pre-column, 30 m, 0.32 mm i.d., 0.40 - 0.45 p.m film tliickness cairier gas He, 90 KPa (stand-by position) and 170 KPa (cut position) oven temperature, 45 °C (6 min)-240 °C at 2 °C/min diethyl-tert-butyl-/3-cyclodextrin column, 25 m X 0.25 mm i.d., 0.25 p.m film thickness cairier gas He, 110 KPa (stand-by position) and 5 KPa (cut position) oven temperature, 45 °C (6 min), rising to 90 °C (10 min) at 2 °C/min, and then to 230 °C at 2 °C/min. Reprinted from Journal of High Resolution Chromatography, 22, L. Mondello et al, Multidimensional capillary GC-GC for the analysis of real complex samples. Part IV. Enantiomeric distribution of monoterpene hydrocarbons and monoterpene alcohols of lemon oils , pp. 350-356, 1999, with permission from Wiley-VCH.

Figure 12.7 Cliromatograms of a polycarbonate sample (a) microcolumn SEC ti ace (b) capillary GC ti ace of inti oduced fractions. SEC conditions fused-silica (30 cm X 250 mm i.d.) packed with PL-GEL (50 A pore size, 5 mm particle diameter) eluent, THE at aElow rate of 2.0ml/min injection size, 200 NL UV detection at 254 nm x represents the polymer additive fraction ti ansfeired to EC system (ca. 6 p-L). GC conditions DB-1 column (15m X 0.25 mm i.d., 0.25 pm film thickness) deactivated fused-silica uncoated inlet (5 m X 0.32 mm i.d.) temperature program, 100 °C for 8 min, rising to 350 °C at a rate of 12°C/min flame ionization detection. Peak identification is as follows 1, 2,4-rert-butylphenol 2, nonylphenol isomers 3, di(4-tert-butylphenyl) carbonate 4, Tinuvin 329 5, solvent impurity 6, Ii gaphos 168 (oxidized). Reprinted with permission from Ref. (14).

Figure 12.18 LC-SFC analysis of mono- and di-laurates of poly (ethylene glycol) ( = 10) in a surfactant sample (a) normal phase HPLC trace (b) chromatogram obtained without prior fractionation (c) chromatogram of fraction 1 (FI) (d) chromatogram of fraction 2 (F2). LC conditions column (20 cm X 0.25 cm i.d.) packed with Shimpak diol mobile phase, w-hexane/methylene chloride/ethanol (75/25/1) flow rate, 4 p.L/min UV detection at 220 nm. SFC conditions fused-silica capillary column (15 m X 0.1 mm i.d.) with OV-17 (0.25 p.m film thickness) Pressure-programmed at a rate of 10 atm/min from 80 atm to 150 atm, and then at arate of 5 atm/min FID detection. Reprinted with permission from Ref. (23).

Early work relied on the use of packed columns, but all modern GC analyses are accomplished using capillary columns with their higher theoretical plate counts and resolution and improved sensitivity. Although a variety of analytical columns have been employed for the GC of triazine compounds, the columns most often used are fused-silica capillary columns coated with 5% phenyl-95% methylpolysiloxane. These nonpolar columns in conjunction with the appropriate temperature and pressure programming and pressure pulse spiking techniques provide excellent separation and sensitivity for the triazine compounds. Typically, columns of 30 m x 0.25-mm i.d. and 0.25-qm film thickness are used of which numerous versions are commercially available (e.g., DB-5, HP-5, SP-5, CP-Sil 8 CB, etc.). Of course, the column selected must be considered in conjunction with the overall design and goals of the particular study. 

Oxyfluorfen column, fused-silica capillary column coated with cross-linked methyl silicone (25 m x 0.3-mm i.d., 0.52- am film thickness) temperature, column 200 °C (1 min), 10°Cmin to 250 °C (5 min), inlet and detector 250 and 300 °C, respectively gas flow rates, N2 carrier gas 30mLmin , N2 makeup gas 30mLmin H2 3.5mLmin" air llOmLmin injection volume, 2 p.L. ... 

Chlornitrofen and nitrofen conditions for GC/MS column, cross-linked methyl silicone capillary (12 m x 0.22-mm i.d., 0.33- am film thickness) column temperature, 60 °C (1 min), 18 °C min to 265 °C inlet, transfer line and ion source temperature, 260, 200 and 200 °C, respectively He gas column head pressure, 7.5 psi injection method, splitless mode solvent delay, 3 min electron ionization voltage, 70 eV scan rate, 0.62 s per scan cycle scanned mass range, m/z 100-400. The retention times for chlornitrofen and nitrofen were 11.8 and 11.3 min, respectively. The main ions of the mass spectrum of chlornitrofen were at m/z 317, 319 and 236. Nitrofen presented a fragmentation pattern with the main ions at m/z 283, 202 and 285. ... 

Chlornitrofen in water samples was determined by GC/MS using an SPB-1 fused-silica capillary (15 mx 0.53-mm i.d., 0.5-pm film thickness), with the ionization... 

Fused-silica capillary column, HP-SMS, 30 m x 0.25-mm i.d., 0.25- am film thickness, (5% phenyl)-methylpolysiloxane... 

Hewlett-Packard Model 6890 Fused-silica capillary column, HP 35MS, length 30 m, 0.32-mm i.d., film thickness 0.25-p.m (HP No. 19091G-633)... 

Fused-silica capillary GC column, 15 m x 0.32-mmi.d., coated with trifluoropropyl-methyl polysiloxane (0.5- um film thickness)... 

Chromatographic columns (glass with stopcock and solvent reservoir, 10-mm i.d.) Fused-silica capillary column, DB-1701, 60 m x 0.32-mm i.d., O.lS-qm film thickness (14% cyanopropylphenyl)methylpolysiloxane Varian 3400 gas chromatograph equipped with a temperature-programmed SPI injector, a Varian 8100 autosampler, and a Varian Saturn II lontrap mass spectrometer Centrifuge vials, 10- and 250-mL Evaporation flasks, 100- and 250-mL Separatory funnel, 250-mL... 

Hewlett-Packard model 5890A Fused-silica capillary column, Rtx-200, 0.53-mm i.d., 15-m length, film thickness 1.5- xm (for imibenconazole)... 

Column, gas chromatograph FlP-5, 5% phenyl-methyl capillary column, 0.25-mm i.d. X 12-m length, 0.33-qm film thickness (Agilent Technologies) or equivalent Evaporator, rotary vacuum, water-bath set at 60 and 40 °C Processors ... 

Hewlett-Packard Model 6890 equipped with a nitrogen-phosphorus flame ionization detector Capillary column for gas-liquid chromatography (GLC), DB-1, 0.53-mm i.d. x 15 m, l-pm film thickness (J W Scientific)... 

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