•A type of magnetized anion-exchange metal-organic framework was synthesized.•MOF materials were used for the adsorption of azide firstly.•Combined with IC, the MSPE method offered satisfactory performance for detecting trace azide in sartan drugs.•Compared with previous methods, this approach offers ease of operation, remarkable sensitivity, satisfactory reproducibility and low cost.Quaternary amine functionalized metal-organic framework MIL-101(Cr) (MIL-101(Cr)-NMe3) was prepared as the sorbent for the magnetic solid-phase extraction (MSPE) of azide from sartan drugs before ion chromatography determination. Magnetization of MIL-101-NMe3 were achieved concurrently by adding MIL-101-NMe3 and Fe3O4@SiO2 to the sample solution under ultrasonication. The prepared Fe3O4@SiO2/MIL-101-NMe3 gave the adsorption capacity of 37.5 mg g−1. The developed method had a detection limit of 0.24 μg L−1 and quantitation limit of 0.79 μg L−1 for azide. The relative standard deviations for the intra-day retention time and peak area were 0.52% and 0.36% (n = 5), respectively. The developed method was successfully applied for the determination of azide in sartan drugs with the recoveries from 96.5% to 100.5%.

Mass spectrometry (MS) is the most powerful tool in phosphoproteomics research. However, phosphopeptides usually are present in low concentrations and their preconcentration therefore is highly desired. We describe a two-step method for the synthesis of a metal organic framework of the type MIL-101(Cr) that is modified with urea (then designated as MIL-101(Cr)-UR2). It possesses large surface area, good solvent stability and high affinity for some phosphates. Due to the presence of modified urea functions, this material allows for selective and effective enrichment of phosphorylated peptides. It was successfully applied to the enrichment of phosphopeptides from non-fat-milk. The method was applied to the detection of phosphopeptides in a tryptic digest of β-casein where is showed a detection sensitivity as low as 10−10 M.

•We developed a combined procedure for the fast and selective enrichment of phosphopeptides.•TEMSN was used as a bioreactor for digestion of α-casein within 3 min.•ZrO2-MSN possessed remarkable selectivity even at 100/1 molar ratio of BSA/β-casein.•The detection limit was as low as 2.5 fmol.•This analytical strategy got a comparable results in comparison to other materials cited from literature.Trypsin functionalized mesoporous silica nanotubes bioreactor (TEMSN) and zirconia layer coated mesoporous silica nanotubes (ZrO2-MSN) were developed to deal with the long in-solution digestion time of phosphoprotein and detection difficulty of phosphorylated peptides, respectively. Trypsin was immobilized on the mesoporous silica nanotubes via epoxy group and TEMSN were used as a bioreactor for digestion of α-casein within 3 min. ZrO2-MSN were performed to enrich phosphopeptides selectively from in-solution digested peptide mixture of β-casein to demonstrate that ZrO2-MSN possessed remarkable selectivity for phosphorylated peptides even at 100/1 molar ratio of BSA/β-casein. The selective ability of ZrO2-MSN was also investigated in comparison to ZrO2 nanoparticles (ZrO2 NP). Moreover, phosphorylated peptides at the femtomole (2.5 fmol) level can also be detected with high S/N (signal-to-noise) ratio. Phosphopeptides enriched from TEMSN-bioreactor digested peptide mixture of α-casein was also performed to evaluate the cooperative performance of TEMSN and ZrO2-MSN platform. The experimental results indicated that TEMSN-bioreactor digestion changed the distribution of relative abundance of phosphopeptides and improved the relative intensity of partial phosphopeptides. This analytical strategy has also been applied to the identification of phosphopeptides isolated from non-fat bovine milk and got a comparable results compared with other materials cited from the literature. By matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS), TEMSN and ZrO2-MSN were combined together for the rapid and comprehensive analysis of phosphoprotein.

•A new dimethylethanolamine amination polychloromethyl styrene nano-latex (DMEAPL) was synthesized.•DMEAPL coated capillary column (ccc-DMEAPL) was prepared and it provided the steady EOF within acidic pH range.•Sensitive determination of tetracycline antibiotics (TCs) in pig plasma were developed by field-amplified sample stacking OT-CEC with ccc-DMEAPL.This paper described the preparation and application of a new dimethylethanolamine aminated polychloromethyl styrene nano-latex (DMEAPL) coated capillary column (ccc-DMEAPL) in the determination of four tetracycline antibiotics (TCA) including tetracycline (TC), oxytetracycline (OTC), doxycycline (DC) and chlorotetracycline (CTC) in pig plasma. The ccc-DMEAPL column was characterized with steady EOF values of ca. 1.5–5.2 × 10−5 cm2/V s at pH 1.8–6.3. The optimized conditions for field-amplified sample stacking open-tubular capillary electrochromatography (FASS-OT-CEC) were as following: background electrolyte, 10 mmol/L Na2HPO4 + 15 mmol/L citric acid (pH 3.2); ccc-DMEAPL, 50 μm i.d. × 50 cm (effective length 41.5 cm), separation voltage, 18 kV; column temperature, 25 °C; UV detection wavelength, 270 nm; water-plug injection: 30 mbar × 10 s; sample electrokinetic injection, 10 kV × 20 s. The four TCA were extracted with the solution of 10 mmol/L Na2HPO4 + 15 mmol/L citric acid + 4 g/L EDTA-2Na (pH 3.2). The FASS-OT-CEC method was validated in terms of linearity, sensitivity, selectivity, precision and accuracy. The LODs ranged from 3 to 7 ng/mL, the recoveries for the four TCA were all more than 80%. The developed method was successfully applied for the determination of TCs in the actual pig plasma samples.

A new nano-scale restricted-access matrix (RAM) SiO2 (MCM-41) with relatively high Ti-content (Ti/Si = 0.1), but superior surface area (1129 m2/g), was successfully synthesised for the enrichment of phosphopeptides. The TiO2 was incorporated into the Si-MCM-41 via a hydrothermal process and the external surface was modified with alkyl diol by the successive hydrolysis of γ-(glycidyloxypropyl) trimethoxysilane (GPTMS). Scanning electron microscopy, transmission electron microscopy, N2 adsorption and Fourier transform infrared spectroscopy were used to characterise the alkyl diol-Ti-MCM-41. The appropriate pore diameter (2 nm) coupled to the marshy weeds-like hydrophilic external surface result in an efficient size-exclusion effect for the adsorption of standard cytochrome c with a molecular weight (MW) of ca. 12.4 kDa. At the same time, the strong affinity interaction between the incorporated titanium in the framework and the phosphoryl groups of phosphopeptides demonstrated a selective extract of phosphopeptides from the tryptic digestion. The detection sensitivity for phosphopeptides, determined by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) was as low as 5 fmol for standard tryptic digest of β-casein. Therefore, this alkyl diol-Ti-MCM-41 mesoporous material can be used as a potential adsorbent for applications in MS-based phosphoproteomics.Highlights► We synthesised Ti incorporated mesoporous SiO2 (MCM-41) as a restricted-access matrix adsorbent. ► We modified the external surface with alkyl diol. ► We characterised it with SEM, TEM, N2 adsorption and FT-IR. ► This material demonstrates a selective extract of phosphopeptides from the tryptic digestion. ► The sensitivity of detection for phosphopeptides determined by MALDI-TOF MS was as low as 5 fmol.