Significance and Use
5.1 This practice is intended to be used by all analysts using fused silica capillary chromatography. It contains the recommended steps for installation, preparation, proper installation, and continued column maintenance.
1. Scope
1.1 This practice covers the installation and maintenance of fused silica capillary columns in gas chromatographs that are already retrofitted for their use. This practice excludes information on: 1.1.1 Injection techniques. 1.1.4 System troubleshooting and maintenance. 1.2 For additional information on gas chromatography, please refer to Practice E260. For specific precautions, see 7.2.2.2(1), 7.2.2.2(2), 7.2.7, and 7.2.7.2. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific safety information, see Section 6, 7.2.2.2(1), 7.2.2.2(2), 7.2.7, and 7.2.7.2. TABLE 1 Typical Splitter Vent Flow Rates (50 to 1 split ratio) (at optimum linear velocity) | Carrier gas | 0.25-mm ID, cm3 /min | 0.32-mm ID, cm3 /min | 0.53-mm ID, cm3 /min | | helium hydrogen | 35 70 | 80 160 | 125 250 | Note 1— The curves were generated by plotting the height equivalent to a theoretical plate (length of column divided by the total number of theoretical plates, H.E.T.P.) against the column's average linear velocity. The lowest point on the curve indicates the carrier gas velocity in which the highest column efficiency is reached. Note 2— Gases information available from Compressed Gas Association (CGA), 4221 Walney Rd., 5th Floor, Chantilly, VA 20151-2923, http://www.cganet.com. FIG. 1 Van Deemter Profile for Hydrogen, Helium, and Nitrogen Carrier Gases  | Carrier gas: Hydrogen | Carrier gas: Helium | | Linear velocity: 40 cm/s | Linear velocity: 20 cm/s | Note 1— Fig. 2 shows that the resolution is similar but the analysis time is reduced by 50 % when comparing hydrogen to helium in an isothermal analysis using optimum flow velocities. Note 2— Hydrogen provides similar resolution in one-half the analysis time of helium for an isothermal analysis. Note 3— | | 1. Tetrachloro-m-
| 8. Heptachlor epoxide | 15. Endosulfan II | | | xylene | 9. γ-chlordane | 16. DDD | | | 2. α-BHC | 10. Endosulfan I | 17. Endrin aldehyde | | | 3. β-BHC | 11. α-chlordane | 18. Endosulfan sulfate | | | 4. γ-BHC | 12. Dieldrin | 19. DDT | | | 5. δ-BHC | 13. DDE | 20. Endrin ketone | | | 6. Heptachlor | 14. Endrin | 21. Methyoxychlor | | | 7. Aldrin | | | Note 4— 30 m, 0.25-mm ID, 0.25 μm 5 % diphenyl − 95 % dimethyl polysiloxane 0.1-μL split injection of chlorinated pesticides. | | Oven temperature: 210°C isothermal | | | Injector and detector temperature: 250°C/300°C | | | ECD sensitivity: 512 × 10 −11 | | | Split vent: 100 cm 3 /min |
FIG. 2 Hydrogen Versus Helium (Isothermal Analysis) FIG. 3 Capping Silanol Groups with Dimethyl Dichlorosilane (DMDCS) Note 1— Septum bleed can obscure or co-elute with compounds of interest, thus decreasing the analytical accuracy. Note 2— | | 1. 2,4,5,6-tetrachloro- | 8. Heptachlor
| 16. p,p-DDD | | | m-xylene (IS) | epoxide | 17. Endrin aldehyde | | | 2. α-BHC | 9. γ-chlordane | 18. Endosulfan sul- | | | 3. β-BHC | 10. Endosulfan I | fate | | | 4. γ-BHC | 11. α-chlordane | 19. p,p-DDT | | | 5. δ-BHC | 12. Dieldrin | 20. Endrin ketone | | | 6. Heptachlor | 13. p,p-DDE | 21. Methyoxychlor | | | 7. Aldrin | 14. Endrin | 22. Decachlorobi- | | | | 15. Endosulfan II | phenyl (IS) |
Note 3— 30 m, 0.53-mm ID, 0.50 μm 5 % diphenyl − 95 % dimethyl polysiloxane 0.1 μL direct injection of 50 pg pesticide standard. | Oven temperature: 150 to 275°C at 4°C/min, hold 15 min | | | Injector temperature: 250°C | Detector temperature: 300°C | | Carrier gas: Helium | | | Linear velocity: 40 cm/s (Flow rate: 10 cm 3 /min) | | | ECD sensitivity: 8 × 10 −11 AFS | | FIG. 4 ECD Septum Bleed
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM Standards
E260 Practice for Packed Column Gas Chromatography
E355 Practice for Gas Chromatography Terms and Relationships
CGA Publications
HB-3 Handbook of Compressed Gases
Keywords
capillary columns; capillary gas chromatography; gas chromatographs; installing capillary columns;
ICS Code
ICS Number Code 71.040.50 (Physicochemical methods of analysis)
DOI: 10.1520/E1510-95R13E01
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Citing ASTM Standards
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