Injector‐internal thermal desorption from edible oils. Part 1: Visual experiments on sample deposition on the liner wall

Biedermann, Maurus; Fiselier, Katell; Grob, Koni

doi:10.1002/jssc.200500033

Cited by 21 publications

(7 citation statements)

References 12 publications

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“…The lipid phase of the marking fluid was analyzed by GC and GC-MS for its volatile organic content using the injector-internal thermal desorption technique (Biedermann et al 2005). Aliquots of approximately 3 to 4 mg of the lipid material were applied to the inside wall of an injector liner containing just enough silylated glass wool to prevent the lipid sample from running down the liner to the bottom of the injector.…”

Section: Solventless Sample Introduction Of the Lipid Fractionmentioning

confidence: 99%

Chemical Characterization of Territorial Marking Fluid of Male Bengal Tiger, Panthera tigris

Burger

Viviers

Bekker³

et al. 2008

J Chem Ecol

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The territorial marking fluid of the male Bengal tiger, Panthera tigris, consists of a mixture of urine and a small quantity of lipid material that may act as a controlled-release carrier for the volatile constituents of the fluid. Using gas chromatography and gas chromatography-mass spectrometry, 98 volatile compounds and elemental sulfur were identified in the marking fluid. Another 16 volatiles were tentatively identified. The majority of these compounds were alkanols, alkanals, 2-alkanones, branched and unbranched alkanoic acids, dimethyl esters of dicarboxylic acids, γ-and δ-lactones, and compounds containing nitrogen or sulfur. Several samples of the marking fluid contained pure (R)-3-methyl-2-octanone, (R)-3-methyl-2-nonanone, and (R)-3-methyl-2-decanone, but these ketones were partly or completely racemized in other samples. The γ-lactone (S)-(+)-(Z)-6-dodecen-4-olide and the C8 to C16 saturated (R)-γ-lactones and (S)-δ-lactones were present in high enantiomeric purities.The chiral carboxylic acids, 2-methylnonanoic acid, 2-methyldecanoic acid, 2-methylundecanoic acid, and 2-ethylhexanoic acid were racemates. Cadaverine, putrescine, and 2-acetylpyrroline, previously reported as constituents of tiger urine, were not detected. The dominant contribution of some ketones, fatty acids, and lactones to the composition of the headspace of the marking fluid suggests that these compounds may be important constituents of the pheromone. Although it constitutes only a small proportion, the lipid fraction of the fluid contained larger quantities of the volatile organic compounds than the aqueous fraction (urine). The lipid derives its role as controlled-release carrier of the chemical message left by the tiger, from its affinity for the volatiles of the marking fluid. Six proteins with masses ranging from 16 to 69 kDa, inter alia, the carboxylesteraselike urinary protein known as cauxin, previously identified in the urine of the domestic cat and other felid species, were identified in the urine fraction of the marking fluid.

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Section: Solventless Sample Introduction Of the Lipid Fractionmentioning

confidence: 99%

Chemical Characterization of Territorial Marking Fluid of Male Bengal Tiger, Panthera tigris

Burger

Viviers

Bekker³

et al. 2008

J Chem Ecol

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“…The technique elaborated for a conventional (isothermal) injector was characterized by the following elements [1,2]: (i) The sample is injected by band formation, i. e., suppressing thermospray from partial solvent evaporation in the syringe needle [9]. (ii) Conditions ensure that the sample liquid is deposited on the liner wall, which means the use of solvents of a boiling point sufficiently high to avoid rejection of the sample liquid by a cushion of vapor, and oil concentrations not exceeding 20-30% in order to avoid squirting.…”

Section: Conventional Vaporizing Injectormentioning

confidence: 99%

“…Thermal desorption from edible oil in a conventional vaporizing GC injector [1,2] was described as a simple technique for the analysis of compounds of up to rather high boiling points in oils and fats or extracts of fatty foods. The oil-containing solution is deposited on the wall of the injector liner.…”

Section: Introductionmentioning

confidence: 99%

Injector‐internal thermal desorption from edible oils performed by programmed temperature vaporizing (PTV) injection

Fankhauser-Noti¹,

Grob²

2006

J of Separation Science

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Injector-internal thermal desorption is a promising technique for the analysis of a wide range of food components (e.g., flavors) or food contaminants (e.g., solvent residues, pesticides, or migrants from packaging materials) in edible oils and fats or fatty food extracts. Separation from the fatty matrix occurs during injection. Using programmed temperature vaporizing (PTV) injection, the oily sample or sample extract was deposited on a small pack of glass wool from which the components of interest were evaporated and transferred into the column in splitless mode, leaving behind the bulk of the matrix. Towards the end of the analysis, the oil was removed by heating out the injector and backflushing the precolumn. The optimization dealt with the gas supply configuration enabling backflush, the injector temperature program (sample deposition, desorption, and heating out), separation of the sample liquid from the syringe needle and positioning it on a support, deactivation of the support surface, holding the plug of fused silica wool by a steel wire, and the analytical sequence maintaining adsorptivity at the desorption site low. It was performed for a mixture of poly(vinyl chloride) (PVC) plasticizers in oil or fatty food. Using MS in SIM, the detection limit was below 0.1 mg/kg for plasticizers forming single peaks and 1 mg/kg for mixtures like diisodecyl phthalate. For plasticizers, RSDs of the concentrations were below 10%; for the slip agents, oleamide and erucamide, it was 12%. The method of incorporating PTV injection was used for about one year for determining the migration from the gaskets of lids for glass jars into oily foods.

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“…As outlined in Part 1 [1], injector-internal thermal desorption means direct injection of somewhat diluted edible oils/ fats or extracts from fatty food into a split/splitless injector. The solutes of interest are evaporated from the oil at a temperature that keeps vaporization of the bulk material low.…”

Section: Introductionmentioning

confidence: 99%

Injector‐internal thermal desorption from edible oils. Part 2: Chromatographic optimization for the analysis of migrants from food packaging material

Fiselier¹,

Biedermann²,

Grob³

2005

J of Separation Science

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Injector-internal thermal desorption from edible oil or fat is a convenient sample preparation technique for the analysis of solutes in lipids or extracts from fatty foods. The injector temperature is selected to vaporize the solutes of interest while minimizing evaporation of the bulk material of the oil. This technique has been in routine use for pesticides for some time. Now its potential is explored for migrants from food contact materials, such as packaging, into simulant D (olive oil) or fatty/oily food, which means extending the range of application towards less volatile compounds. The performance for high boiling components was investigated for diisodecyl phthalate (DIDP) and diundecyl phthalate (DUP). Since the injector temperature needs to be as high as 260degreesC, some bulk material of the oil enters the column and must be removed after every analysis. This is achieved by a coated precolumn backflushed towards the end of each analysis. Desorption of the solutes is particularly efficient in the initial phase, when a thin sample film is spread on the liner wall, and is largely determined by the diffusion speed in the oil after the latter has contracted to droplets. An increased carrier gas flow rate during the splitless period supports the transfer into the column. It is concluded that the technique is attractive for migrant analysis, with DUP being at the upper limit of the boiling point.

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Injector‐internal thermal desorption from edible oils. Part 1: Visual experiments on sample deposition on the liner wall

Cited by 21 publications

References 12 publications

Chemical Characterization of Territorial Marking Fluid of Male Bengal Tiger, Panthera tigris

Chemical Characterization of Territorial Marking Fluid of Male Bengal Tiger, Panthera tigris

Injector‐internal thermal desorption from edible oils performed by programmed temperature vaporizing (PTV) injection

Injector‐internal thermal desorption from edible oils. Part 2: Chromatographic optimization for the analysis of migrants from food packaging material

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