New sample preparation technique for the determination of avoparcin in pressurized hot water extracts from kidney samples

Stationary phases for hydrophilic interaction chromatography, their characterization and implementation into multidimensional chromatography concepts

“…The amide group is usually bonded to the silica gel surface via a short alkyl spacer and, in contrast to amino-groups, does not posses basic properties, so that the retention depends less on pH and irreversible adsorption is less probable [35]. Some amide phases have been specifically designed for use with HILIC, such as, e. g. carbamoyl-silica HILIC TSK-gel Amide-80 [36], poly(2-hydroxyethyl aspartamide) [2], [37], or poly(succinimide) [38]. Monolithic silica gel columns with a polyacrylamide layer prepared by on-column polymerization show improved chemical stability and higher retention in comparison to non-coated monolithic silica [39].…”

Determination of avoparcin in animal tissues and milk using LC‐ESI‐MS/MS and tandem‐SPE

“…These 25 mL of water, 0.2 M H 2 SO 4 in water/ methanol (4:6 v/v) [5,6], water/ethanol (7:3 v/v) [7], 1, 3, and 5% TFA in water, 5% formic acid or 5% acetic acid was added to the centrifuge tube, the mixture was homogenized for 1 min using a YELLOW LINE, D125 basic (IKAm Japan K.K., Nara, Japan) and then the mixture was centrifuged at 6000 rpm (68426g) for 20 min without 0.2 M H 2 SO 4 in water/methanol (4:6 v/v). When 0.2 M H 2 SO 4 was used, the extraction solution was adjusted to pH 4 with 1 M NaOH in water and then the mixture was centrifuged at 6000 rpm (68426g) for 20 min.…”

“…AV-a and -b can be detected under ESI-MS conditions following LC separation. Curren and King [7] reported using an analytical separation with the HILIC method because these analytes are water-soluble. The HILIC method, however, could not resolve AV-a and -b.…”

“…Curren and King [7] reported that the extraction of AV from kidney sample was developed by accelerated solvent system with 30% ethanol at 758C and 50 atm. For this extraction to be achieved, these procedures require specific instruments for pressurized hot system and a large amount of solvents [7].…”

“…The detection limit of AV in chicken muscle is 0.2 lg/g (0.2 ppm) using LC/ amperometric detection [6]. Curren and King [7] reported a method using pressurized hot water extraction of AV from kidney samples with hydrophilic interaction chromatography (HILIC)/UV with a detection limit of 0.5 lg/g (0.5 ppm). The separation and analysis using micellar EKC (MEKC) has a standard solution detection limit of 0.2 lg/mL [8].…”