Covalent bonding of homochiral metal–organic framework in capillaries for amino acid enantiomer separation by capillary electrochromatography.

No abstract

A synthetic polyethylene glycol-molybdenum disulfide (PEG@MoS2) composite was prepared using a simple method, and the application of this material in dispersive solid-phase extraction (DSPE) was investigated for the enrichment of eight sulfonamides (SAs) in milk samples. The composite was characterized by energy dispersive spectroscopy, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller measurements. The results showed that the MoS2 synthesized in the presence of PEG has the advantage of a larger surface area and that the adsorption effect of this MoS2 was enhanced. After extraction, the eight SAs were separated by capillary zone electrophoresis with a good linear relationship (R2 > 0.9902) in the range of 0.3–30 µg ml−1 and good precision (between 0.32% and 9.83%). Additionally, good recoveries (between 60.52% and 110.91%) were obtained for the SAs in the milk samples. The developed PEG@MoS2-based DSPE method could be applied for the enrichment of SAs in real milk samples.

No abstract

In this research, molybdenum disulfide (MoS2) was used as an adsorbent in dispersive solid‐phase extraction (DSPE) for the pretreatment of sulfonamides (SAs) in water samples. Four types of SA (sulfadimidine, sulfathiazole, sulfadiazine, and sulfamethoxazole) were enriched by DSPE. Parameters for DSPE, including extraction time and elution time, were investigated. After pretreatment using DSPE, the SAs were separated by capillary zone electrophoresis (CZE) under optimal analytical conditions. A linear relationship was shown for these SAs in the ranges of 0.5‐50 and 0.5‐30 μg/mL, and the linearity (R2 > 0.9911) and precision (between 0.65% and 9.10%) were good. Thus, this analytical technique can achieve stable, reproducible and efficient separation of SAs, and the developed DSPE method enables the preconcentration of SAs from environmental water samples.