Retention behaviour of some high-intensity sweeteners on different SPE sorbents.
The objective of this paper is to provide information about application of solid-phase extraction (SPE) for isolation of nine high-intensity sweeteners (acesulfame-K, alitame, aspartame, cyclamate, dulcin, neotame, saccharin, sucralose and neohesperidin dihydrochalcone) from aqueous solutions. The influence of several types of LC-MS compatible buffers (different pH values and compositions) on their recovery has been studied and discussed. A number of commercially available SPE cartridges, such as Chromabond C18ec, Strata-X RP, Bakerbond Octadecyl, Bakerbond SDB-1, Bakerbond SPE Phenyl, Oasis HLB, LiChrolut RP-18, Supelclean LC-18, Discovery DSC-18 and Zorbax C18 were tested in order to evaluate their applicability for the isolation of analytes. Very high recoveries (better than 92%) of all studied compounds were obtained using formic acid-N,N-diisopropylethylamine buffer adjusted to pH 4.5 and C(18)-bonded silica sorbents. Behaviour of polymeric sorbents strongly depends on their structure. Strata-X RP behaves much like a C(18)-bonded silica sorbent. Recoveries obtained using Oasis HLB were comparable with those observed for silica-based sorbents. The only compound less efficiently (83%) retained by this sorbent was cyclamate. Bakerbond SDB-1 shows unusual selectivity towards aspartame and alitame. Recoveries of these two sweeteners were very low (26 and 42%, respectively). It was also found that aspartame and alitame can be selectively separated from the mixture of sweeteners using formic acid-triethylamine buffer at pH 3.5.
Zygler
Agata
A
Gdańsk University of Technology, Chemical Faculty, Department of Analytical Chemistry, ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland. agatazygler@wp.pl
Wasik
Andrzej
A
Namieśnik
Jacek
J
D000327:Adsorption; D002021:Buffers; D002851:Chromatography, High Pressure Liquid; D005021:Ethylamines / Q000737:chemistry*; D005561:Formates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D012015:Reference Standards; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D013549:Sweetening Agents / Q000032:analysis*
D002021:Buffers; D005021:Ethylamines; D005561:Formates; D013549:Sweetening Agents; C030544:formic acid; D012822:Silicon Dioxide; C016162:triethylamine