Determination of low levels of an antioxidant in polyolefins by large-volume injection temperature-programmed packed capillary liquid chromatography

Molander, Paal; Haugland, K.; Hegna, D. R.; Ommundsen, Espen; Lundanes, Elsa; Greibrokk, Tyge

doi:10.1016/s0021-9673(99)01006-7

Cited by 51 publications

(40 citation statements)

References 26 publications

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“…Typical injection volumes in capillary LC are 0.05 -0.1 lL. However, micro LC with packed capillary columns can advantageously be used for trace determination of analytes in samples of limited sample size [54] by utilizing large volume injections, where the sample can be introduced either by on-column focusing techniques [55] or by column switching techniques [56,57].…”

Section: Applicationsmentioning

confidence: 99%

“…The repeatability of retention time with temperature programs has been determined to be in the range 0.5 -1.4% RSD for a 30 -1508C (at 1.5 K/min) gradient [107], 0.4 -1.2% RSD for a 7 -908C (at 3 K/min) gradient [55] and 2% RSD for a 30 -1208C (at 5 K/min) gradient [131], using polyglycerol fatty acid esters [107] and Irganox 1076 [55,131] as test compounds. Thus the repeatability of retention time in temperature gradient mode (0.5 -1.4% RSD) was found to be in the same range as in solvent gradient mode (0.3 -1.7% RSD) [107].…”

Section: Instrumentationmentioning

confidence: 99%

“…Nevertheless, a limited number of papers have also shown the applicability of this methodology for real samples [55,57,96,106,110,111,115,116]. In all these cases the temperature has been used actively for retention control.…”

Section: Applicationsmentioning

confidence: 99%

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Controlling the retention in capillary LC with solvents, temperature, and electric fields

Jandera

Blomberg

Lundanes³

2004

J of Separation Science

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Once a suitable stationary phase and column dimensions have been selected, the retention in liquid chromatography (LC) is traditionally adjusted by controlling the mobile phase composition. Solvent gradients enable achievement of good separation selectivity while decreasing the separation time as compared to isocratic elution. Capillary columns allow use of other programming parameters, i.e. temperature and applied electric fields, in addition to solvent gradient elution. This paper presents a review of programmed separation techniques in miniaturized LC, including retention modeling and method transfer from the conventional to micro- and capillary scales. The impact of miniaturized instrumentation on retention and the limitations of capillary LC are discussed. Special attention is focused on the gradient dwell volume effects, which are more important in micro-LC techniques than in conventional analytical LC and may cause significant increase in the time of analysis, unless special instrumentation and (or) pre-column flow-splitting is used. The influence of temperature upon retention is also discussed, and applications where the temperature has been actively used for retention control in capillary LC are included together with the instrumentation utilized. Finally the possibilities of additional selectivity control by applying an electric field over a packed capillary LC column are discussed.

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Section: Applicationsmentioning

confidence: 99%

Section: Instrumentationmentioning

confidence: 99%

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Controlling the retention in capillary LC with solvents, temperature, and electric fields

Jandera

Blomberg

Lundanes³

2004

J of Separation Science

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“…Today, lower temperatures are used mainly for chiral separations, which are hampered by the lack of commercially available instrumentation. Reduced temperatures can also be used for large-volume sample introduction, with or without solvent focusing (18).…”

Section: Applicationsmentioning

confidence: 99%

Peer Reviewed: Heating or Cooling LC Columns

Greibrokk¹

2002

Anal. Chem.

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“…Consequently, the temperature may be lowered to a point where the analytes are totally retained on the column entrance, allowing sample volumes up to 500 lL to be injected on a capillary column without column overloading [2,17], analogous to the more traditional method of dissolving the solutes that are to be enriched in solvent mixtures of non-eluting properties. In fact, the exploitation of sub-ambient temperature assisted large volume solute enrichment might be an asset in certain cases where the solutes are of limited solubility in solvent mixtures with non-eluting properties at ambient temperatures, allowing the use of stronger solvents [2,3,17]. In general, large volume injection is especially favourable when working with limited sample amounts as total sample exploitation is often accessible.…”

Section: Introductionmentioning

confidence: 99%

Novel column oven concept for cold spot large volume sample enrichment in high throughput temperature gradient capillary liquid chromatography

Holm¹,

Molander

Lundanes

et al. 2003

J of Separation Science

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Novel column oven concept for cold spot large volume sample enrichment in high throughput temperature gradient capillary liquid chromatography A novel column oven concept with an incorporated cold spot has been tailored for use in capillary liquid chromatography, allowing efficient injection of increased sample volumes by sub-ambient temperature-promoted solute enrichment. The column oven system consists of two horizontally connected temperature zones surrounding the packed capillary column. The oven is designed to allow horizontal sliding of the capillary column inside the column oven housing, enabling rapid transportation of the column inlet between the two temperature zones. This design eliminates the time consuming process of re-cooling the oven after a temperature gradient, which is associated with other column ovens, providing the possibility of high throughput analyses. The cold inlet zone of the oven was operated at sub-ambient temperatures where elution is suppressed to allow enrichment of large volumes of solutes dissolved in solvents usually associated with high eluting properties. The hot column oven zone allowed temperature-programmed gradient action, but could also be operated isothermally resulting in a temperature step gradient. The oven was evaluated using the antioxidants Irgafos 168, Irgafos 168-phosphate, and Irganox 1076 as model compounds using UV-detection. A 3.5 lm Kromasil C 18 0.25 mm ID620 cm capillary column was used, while the mobile phase and the sample solvent was neat acetonitrile. The flow rate was 5 lL/min. Within-assay precision and between-assay precision of peak areas were in the range of 4.3 -8.2% relative standard deviation (RSD). The retention time RSD in temperature gradient mode was 2%. The method was linear in the investigated range of 5 -100 ng, displaying a correlation coefficient of 0.9995.

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Determination of low levels of an antioxidant in polyolefins by large-volume injection temperature-programmed packed capillary liquid chromatography

Cited by 51 publications

References 26 publications

Controlling the retention in capillary LC with solvents, temperature, and electric fields

Controlling the retention in capillary LC with solvents, temperature, and electric fields

Peer Reviewed: Heating or Cooling LC Columns

Novel column oven concept for cold spot large volume sample enrichment in high throughput temperature gradient capillary liquid chromatography

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