This work focused on the development and validation of the analytical procedure using gas chromatography equipped with vacuum-ultraviolet detection for the specific and sensitive determination of nine photoinitiators in food packages. Subsequently, a comparison of the combination of vacuum ultraviolet spectroscopy with gas chromatography and a developed gas chromatography with mass spectrometry method was performed. The vacuum-ultraviolet spectra of all tested photoinitiators were collected and found to be highly distinct, even for isomers. Under the optimal conditions, the limits of detection for nine photoinitiators ranged from 1 to 5 mg/L using vacuum ultraviolet detection and from 0.15 to 0.5 mg/L using mass spectrometric detection. Both techniques were successfully applied for screening of photoinitiators in seven kinds of food packages and the obtained data showed good agreement (the relative difference was between 3 and 18%). The variability in concentrations found in triplicate samples was assessed to be below 18%. Predominantly benzophenone was found in all analysed samples in the range of 0.31-4.23 mg/kg. It appears to be preferably selected by food packaging manufacturers. This study proposes a new simple and sensitive technique used for analysis of photoinitiators that could be a good alternative to gas chromatography with mass spectrometry.
- Klíčová slova
- food packaging, food safety, gas phase absorption spectroscopy, leaching, photoinitiators,
- MeSH
- benzofenony analýza MeSH
- fotosenzibilizující látky analýza MeSH
- inkoust * MeSH
- kontaminace potravin analýza MeSH
- obaly potravin * MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- spektrofotometrie ultrafialová MeSH
- vakuum MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- benzofenony MeSH
- benzophenone MeSH Prohlížeč
- fotosenzibilizující látky MeSH
Distinguishing isomeric representatives of "bath salts", "plant food", "spice", or "legal high" remains a challenge for analytical chemistry. In this work, we used vacuum ultraviolet spectroscopy combined with gas chromatography to address this issue on a set of forty-three designer drugs. All compounds, including many isomers, returned differentiable vacuum ultraviolet/ultraviolet spectra. The pair of 3- and 4-fluoromethcathinones (m/z 181.0903), as well as the methoxetamine/meperidine/ethylphenidate (m/z 247.1572) triad, provided very distinctive vacuum ultraviolet spectral features. On the contrary, spectra of 4-methylethcathinone, 4-ethylmethcathinone, 3,4-dimethylmethcathinone triad (m/z 191.1310) displayed much higher similarities. Their resolution was possible only if pure standards were probed. A similar situation occurred with the ethylone and butylone pair (m/z 221.1052). On the other hand, majority of forty-three drugs was successfully separated by gas chromatography. The detection limits for all the drug standards were in the 2-4 ng range (on-column amount), which is sufficient for determinations of seized drugs during forensics analysis. Further, state-of-the-art time-dependent density functional theory was evaluated for computation of theoretical absorption spectra in the 125-240 nm range as a complementary tool.
- Klíčová slova
- Bath salts, Fourier transform ion cyclotron resonance, Gas phase absorption, Isomeric drugs, Time-dependent density functional theory, VUV absorption spectroscopy,
- MeSH
- chromatografie plynová * MeSH
- isomerie MeSH
- nové syntetické drogy analýza MeSH
- spektrální analýza * MeSH
- stimulanty centrálního nervového systému analýza MeSH
- vakuum MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- nové syntetické drogy MeSH
- stimulanty centrálního nervového systému MeSH
Cyclofructans and preferentially their derivatives can serve as chiral selectors for the separation of different enantiomers/atropisomers. Moreover, the strong ionophoric nature of the 18-crown-6 ether core of cyclofructan 6 for barium cations may be exploited to enhance or modify enantioselectivity. In this work isopropyl-cyclofructan-6 was used as a chiral selector for the separation of binaphthyl atropisomers in HPLC and CE. The data from both separation systems were compared with each other. While in HPLC the chiral selector was bonded to silica gel to afford a chiral stationary phase, in capillary electrophoresis it was freely mobile in the background electrolytes (BGE). This significant difference is reflected in the separation potential of the two separation systems. All five analytes could be baseline separated in HPLC (reversed phase mode) while only one derivative was baseline resolved in CE. This result was attributed to the more rigid nature of the immobilized chiral selector. Addition of Ba(2+) to the mobile phase or BGE improved chiral separations in both systems. The results may help to elucidate the interaction mechanism in these systems with cyclofructan derivatives and to gain some general knowledge of their separation potential.
- Klíčová slova
- Atropisomer, Capillary electrophoresis, Chiral separation, Cyclofructan, High performance liquid chromatography, Isopropyl-cyclocfructan-6,
- MeSH
- chromatografie s reverzní fází metody MeSH
- elektroforéza kapilární metody MeSH
- elektrolyty MeSH
- fruktany analýza chemie MeSH
- stereoizomerie MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cyclofructan 6 MeSH Prohlížeč
- elektrolyty MeSH
- fruktany MeSH
