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Recently, it was reported that polyamines, such as spermidine and spermine, play an important role in the inhibition of Leukocyte Function Antigen-1 (LFA-1) related to the induction of inflammation, immune function, and the arteriosclerosis process. 8,9 Since polyamines orally taken are directly absorbed, more attention has been given to food rich in polyamines for the possibility of controlling arteriosclerosis.Both pre-column and post-column derivatization methods for amine analyses have been extensively used in HPLC to improve the sensitivity and selectivity.10-17 A post-column derivatization method is the much preferred method for amines, because it offers easy operation, less sample manipulation, and high 2013 © The Japan Society for Analytical Chemistry † To whom correspondence should be addressed. We investigated the efficacy and utility of a post-column derivatization method for the detection of amines with o-phthalaldehyde (OPA) in ultra high-performance liquid chromatography (UHPLC). Since it was anticipated that a derivatization reaction system placed downstream of the column would give considerable band broadening to narrow peaks generated by a UHPLC column, we examined the contributions of the dimensions of the reaction tube, the fluorescence (FL) detector flow cell, and the column to the extra-column peak broadening, and optimized the post-column derivatization system in UHPLC. We successfully separated amines within 6 min with gradient elution by using the post-column derivatization system connected to a UHPLC system. The analysis time was reduced by a factor of 7 compared with that by conventional HPLC. The detection limits were 18.0 -105.7 fmol, depending on the compounds; the reproducibilities were 0.11 -0.82% RSD for the retention times and 0.78 -1.66% RSD for the peak areas (n = 10), respectively. The linear dynamic ranges were up to 12, 20, and 40 pmol/μL, depending on the compounds, respectively.

Successful separation of triglycerides, diglycerides, free fatty acids, carotenes, tocopherol, and tocotrienols from crude palm oil has been achieved by supercritical fluid chromatography (SFC) with a combination of a C18 and a silica gel column. The separation was carried out by the programmed extraction elution method. Free fatty acids were separated into five components by gas‐liquid chromatography; tocopherol and tocotrienols were also separated into four components by SFC analysis, and the pure fractionated carotenes were obtained by preparative SFC. Thus, by using supercritical fluid chromatography, crude palm oil components can be separated and fractionated, based on differences in their functional groups.

KeywordsEnantiomer ratio, d,l-carvone, caraway seeds, speamint leaves, polarimetric detector, supercritical fluid extractionThe determination of enantiomer ratios of optical isomers has been an important subject in pharmaceutical chemistry, biochemistry, clinical chemistry, and agricultural chemistry because the optical isomers often differ in biological activity.There are two methods for the determination of enantiomer ratios by high-performance liquid chromatography (HPLC). One employs the chromatographic enantiomer separation which can be achieved either by using a chiral stationary phase or chiral mobile phase or by derivatization into diastereomers. The other is based on the simultaneous detection of optical rotation and UV absorption. In the latter method, the apparent optical rotation representing the sum of optical rotations of d and l-type, and the UV absorption representing the total amount, are measured by polarimetric detector and UV detector, respectively. The d/ l ratio can be obtained from a calibration curve established by the response of the polarimeter and the UV detector for a known amount of d-or l-isomer. Here one assumes the response of the polarimeter becomes zero when d/1=1, whereas that of the UV detector is simply proportional to the total amount.An advantage of this method over the first one is that chromatographic separation of optical isomers is not necessary.Therefore, this method is quite useful when enantiomer separation is difficult. Thus, the strategy has been employed in the determination of enantiomer ratios of permetric acid pentafluorobenzylesterl, d,/-epinephrine2, pyrethroids3, amino acids4, and DP-1904.5 In this report, the compositional ratios of d-and 1-enantiomers of carvone in essential oils were determined by HPLC with simultaneous detection of optical rotation and UV absorption.Essential oils were extracted from caraway seeds and dry speamint leaves by supercritical fluid of carbon dioxide.Caraway seeds contain 100% d-carvone and speamint leaves contain 93% l-carvone and 7% d-carvone. Experimental ApparatusThe HPLC system consisted of a JASCO Model LC-800 series, which included an 880-PU pump, a Rheodyne 7125 injection valve, an 860-CO air circulating oven, an 870-UV variable wavelength UV detector and an 807-IT data processor. Chromatograms were recorded on a RC-250 dual-pen recorder. A DIP-181C polarimeter (JASCO) was used for polarimetric detection. A polarizes and an analyzer used in the polarimeter were made of glam-Thomson prisms. A high pressure mercury lamp was used as light source without a filter. The flow cell had a 50 mm light-path length with an internal volume of 350 µl. A supercritical fluid extraction and chromatography system, JASCO Model Super-200, was employed in the extraction for essential oils from samples. Fig. 1 Structures of carvone enantiomers.

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