Development of a simultaneous multiple solid-phase microextraction-single shot-gas chromatography/mass spectrometry method and application to aroma profile analysis of commercial coffee.

A simultaneous multiple solid-phase microextraction-single shot-gas chromatography mass spectrometry (smSPME-ss-GC/MS) method has been developed for headspace analysis. Up to four fibers (50/30 μm DVB/CAR/PDMS) were used simultaneously for the extraction of aroma components from the headspace of a single sample chamber in order to increase sensitivity of aroma extraction. To avoid peak broadening and to maximize resolution, a simple cryofocusing technique was adopted during sequential thermal desorption of multiple SPME fibers prior to a 'single shot' chromatographic run.

Comparison of volatile constituents extracted from model grape juice and model wine by stir bar sorptive extraction-gas chromatography-mass spectrometry.

A stir bar sorptive extraction (SBSE) method coupled with gas chromatography-mass spectrometry was optimised for the analysis of volatile components of a model wine, based on a previously optimised method used for analysis of the same components in model grape juice. The presence of ethanol in the model wine sample matrix resulted in decreased sensitivity of the method toward most of the volatile constituents. Mean percent relative recoveries and reproducibilities (%CV) were 22.

N-Phenyl-tert-butane-sulfinamide.

In the racemic title compound, C(10)H(15)NOS, the packing exhibits centrosymmetric pairs of mol-ecules linked by N-H⋯O=S hydrogen bonds in a head-to-tail fashion. The N-C(ar-yl) bond [1.4083 (12) Å] is considerably shorter than the N-C(alk-yl) bonds typically found in N-alkyl-alkanesulfinamides (1.

N-(3-Methoxy-phen-yl)-tert-butane-sulfinamide.

In the title compound, C(11)H(17)NO(2)S, the mol-ecules inter-act in a head-to-tail fashion through pairs of N-H⋯O hydrogen bonds, giving discrete centrosymmetric dimers. The N(H)S(O)(t)Bu fragment is disordered over two sets of positions, with the major component comprising 90.0 (2)%.

N-(4-Methoxy-phen-yl)-tert-butane-sulfinamide.

In the title compound, C(11)H(17)NO(2)S, the mol-ecules inter-act head-to-tail through N-H⋯OS hydrogen bonds, giving discrete centrosymmetric cyclic dimers. The N-C(ar-yl) bond length [1.4225 (14) Å] is inter-mediate between that in N-phenyl-tert-butane-sulfinamide [1.

N-Phenyl-adamantane-1-sulfinamide.

In the racemic title compound, C(16)H(21)NOS, the mol-ecules are packed into polymeric chains in the b-axis direction and are linked along the b axis by N-H⋯O and C-H⋯O hydrogen bonds.

N,N-Dibenzyl-methane-sulfonamide.

Mol-ecules of the title compound, C(15)H(17)NO(2)S, which was synthesized from methane-sulfonyl chloride and dibenzyl-amine, are packed in anti-parallel arrays along the c axis, with the methyl group of one mol-ecule dovetailed between the two phenyl rings of the next mol-ecule. Along any such array, the sulfonyl O atoms protrude alternately up and down.

Fast analysis of nicotine in tobacco using double-shot pyrolysis--gas chromatography--mass spectrometry.

A simple, rapid, and sensitive assay of nicotine in tobacco has been developed using pyrolysis-gas chromatography-mass spectrometry (DSP-GC-MS). The optimum pyrolyzer (desorption) conditions, using Korean tobacco grade B1O (0.4 mg) and n-heptadecane as an internal standard, were found to be heating from 50 to 300 degrees C at a rate of 60 degrees C/min.

Comparison of micro-scale simultaneous distillation-extraction and stir bar sorptive extraction for the determination of volatile organic constituents of grape juice.

Traditional micro-scale simultaneous distillation-extraction (SDE) and stir bar sorptive extraction (SBSE) were compared for their effectiveness in the extraction of volatile organic compounds in a synthetic grape juice and a real grape juice (Huxelrebe, a variety of half Muscat ancestry) from an English vineyard. The novel immersion-mode SBSE method, using stir bars with PDMS sorbent, was optimised using the synthetic grape juice. Although mean percent relative recoveries and reproducibilities (%CV) of the SBSE method were inferior to SDE (28.

Determination of optimum conditions for the analysis of volatile components in pine needles by double-shot pyrolysis-gas chromatography-mass spectrometry.

The optimum conditions for the analysis of the volatile organic components of pine needles from Pinus densiflora using double-shot pyrolysis-gas chromatography-mass spectrometry (DSP-GC-MS) were investigated with respect to thermal desorption temperature and duration of heating. A total of 41 compounds were identified using thermal desorption temperatures of 150 degrees C, 200 degrees C, 250 degrees C and 300 degrees C. Thermal decomposition products, which include acetol, acetic acid, furfurals and phenols, were observed only at thermal desorption temperatures exceeding 250 degrees C: they were not observed in the extract from a simultaneous distillation extraction (SDE) method.