Application Notes
Decreasing GC Analysis Time with Small Diameter Columns
Shorter, smaller diameter GC capillary columns shown to decrease analysis time by 50% without loss of resolution for PAH\'s, phenols and lemon oil fingerprint compounds.
Decreasing GC Analysis Time with Small Diameter Columns, Alltech Application Note CA001, 1998.
Shorter capillary columns can result in 50% faster GC analysis. Combined with smaller diameters of 100µm or less, the peak resolution and efficiency and hence, the overall resolution can be maintained.
To demonstrate the reduction in time and acceptable resolution achievable using shorter (10m) and smaller diameter capillary columns (0.05-0.10µm), PAHs, phenols and lemon oil components were chromatographed on these type columns and on standard 30m, 0.25µm capillary columns
A comparison of a standard capillary column (AT-5 Capillary, 30m x 0.25mm x 0.25µm, Part No. 13656) with a high efficiency capillary column (AT-5 Hi-Eff Capillary, 10m x 0.05mm x 0.10µm, Part No. 14428) operated under similar conditions with FID detection at 340°C showed that 16 PAHs: (naphthalene, acenaphthalene, acenapthene, fluorene, phenanthrene, anthracene, fluoranthrene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthrene, benzo(k)fluoranthrene, benzo(a)pyrene, indeno(1,2,3,-cd)pyrene, dibenzo(a,h)anthracene and benzo(ghi)perylene, eluted in less than half the time on the high efficiency column, around 11 minutes.
A similar comparison of 11 phenols (phenol, 2-chlorophenol, 2-nitrophenol, 2,4-dimethylphenol, 2,4-dichlorphenol, 4-chloro-3-methylphenol, 2,4,6-trichlorophenol, 2,4-dinitrophenol, 4-nitrophenol, 2-methyl-4,6-dinitrophenol, and pentachlorophenol) with FID detection at 325°C also showed elution in half the time (11 min. vs. 22).
A lemon oil fingerprint showed a total run time of eight minutes on the high efficiency column with FID detection at 325°C vs. sixteen by the standard column for 27 compounds: a-thulene, a-pinene, camphene, sabinene, b-pinene, 6-methyl-5-hepten-2-one, myrcene, octanal, a-phellandrene, 3-carene, a-terpinene, p-cymene, limonene, g-terpinene, terpinolene, linalool, nonanal, citronellal, terpinen-4-ol, a-terpineol, neral, geranial, neryl acetate, geranyl acetate, b-caryophyllene, trans-a-bergamolene and b-bisabolene.
Key Analyte(s)
2,4-dimethylphenol2,4-dimethylphenol a chlorinated solid is used as an intermediate in phenolic antioxidant production. It is most often measured using GC/FID and GC/MS methods.
2,4-dinitrophenol2,4-dinitrophenol, a crystalline solid used as an intermediate in the production of dyes and wood preservatives is most often measured using GC/FID and GC/MS .
2-chlorophenol2-chlorophenol is a chlorinated liquid used as an intermediate in dye production. It is most often measured using GC/ECD, FID and GC/MS.
Important Analyte(s)
2-methyl-4,6-dinitrophenol
2-nitrophenol2-nitrophenol a chlorinated solid is used as an intermediate in dye production. It is most often measured using GC/FID and GC/MS.
Other Analyte(s)
2,4,6-trichlorophenol2,4,6-trichlorophenol is a chlorinated solid formerly used as a fungicide. It is most often measured using GC/ECD and GC/MS.
2,4-dichlorophenol2,4-dichlorophenol is a chlorinated solid used as an intermediate in herbicide production. It is most often measured using GC/ECD, FID and GC/MS methods.
3-carene3-carene, a colorless liquid hydrocarbon is a natural product and a component of turpentine most often measured in essential oils using GC/FID.
4-chloro-3-methylphenol4-chloro-3-methylphenol is a chlorinated solid used as a fungicide and preservative. It is most often measured using GC/ECD, FID and GC/MS.
More AnalytesEquipment
Alltech Heliflex® AT-5 Capillary ColumnsAlltech Heliflex® AT-5 capillary columns are a line of general purpose non-polar fused silica GC columns manufactured and sold by Alltech Associates.
Technique
GC/FIDIn GC/FID, the FID or flame ionization detector detects analytes by measuring an electrical current generated by electrons from burning carbon particles in the sample.
Source
Alltech Associates, Inc.Alltech Associates, Inc., one of the leading suppliers of HPLC columns, manufactures and distributes HPLC, GC and IC columns, accessories and consumables and maintains a large searchable database of application notes and chromatograms on its website.
