Simultaneous extraction of four plant growth regulators residues in vegetable samples using solid phase extraction based on thiol-functionalized nanofibers mat.

A simple and environmentally friendly sample pretreatment method was established for extraction of four plant growth regulators (PGRs) residues in vegetable samples. In order to effectively extract targets from complex sample matrices, three types of polar groups (COOH, NH2, or SH) functionalized polyacrylonitrile nanofibers mats (PAN NFsM) were prepared and evaluated, respectively. The superior -SH functionalized PAN NFsM was further selected as a novel adsorbent of solid phase extraction (SPE). Under optimal conditions, the proposed method could achieve high sensitivity (0.2-2 ng g-1) and acceptable recovery (88.94%-106.42%) by consuming lower amount of adsorbent (only 5 mg) and organic reagent (only 1.4 mL), and performing much fewer steps than current methods. In addition, the prepared SH-PAN NFsM possessed excellent reusability which could be reused for 6 times without degradation in adsorption capability. These results presented the great potential of the established method for environmental-friendly and efficiently detecting PGRs residues.

Simple, efficient, and eco-friendly sample preparation for simultaneous determination of paracetamol and chloramphenicol in meat.

We have developed and validated a simple, eco-friendly, and reliable method to simultaneously determine paracetamol and chloramphenicol in meat with ultra performance liquid chromatography and tandem mass spectrometry. The samples were firstly extracted with ethylenediaminetetraacetic acid-McIlvaine's buffer and then purified by solid-phase extraction by using a novel core-shell polyaniline/polyacrylonitrile nanofibers mat. Compared with existing methods for the two analytes, the proposed method was simplified greatly with much fewer sample preparation steps, consumed much less time (< 2 min per sample) and organic solvent (0.7 mL per sample). Low detection levels (0.15-0.20 µg/kg for paracetamol, 0.01 µg/kg for chloramphenicol) with good precision and recoveries of the target compounds were obtained. The proposed method was applied to determine the residual paracetamol and chloramphenicol in pork, chicken, and beef samples, and the test results were consistent with those using the Chinese national standard methods, which demonstrates the reliability and practicality of the new method.

The Multivesicular Bodies (MVBs)-Localized AAA ATPase LRD6-6 Inhibits Immunity and Cell Death Likely through Regulating MVBs-Mediated Vesicular Trafficking in Rice.

Previous studies have shown that multivesicular bodies (MVBs)/endosomes-mediated vesicular trafficking may play key roles in plant immunity and cell death. However, the molecular regulation is poorly understood in rice. Here we report the identification and characterization of a MVBs-localized AAA ATPase LRD6-6 in rice. Disruption of LRD6-6 leads to enhanced immunity and cell death in rice. The ATPase activity and homo-dimerization of LRD6-6 is essential for its regulation on plant immunity and cell death. An ATPase inactive mutation (LRD6-6E315Q) leads to dominant-negative inhibition in plants. The LRD6-6 protein co-localizes with the MVBs marker protein RabF1/ARA6 and interacts with ESCRT-III components OsSNF7 and OsVPS2. Further analysis reveals that LRD6-6 is required for MVBs-mediated vesicular trafficking and inhibits the biosynthesis of antimicrobial compounds. Collectively, our study shows that the AAA ATPase LRD6-6 inhibits plant immunity and cell death most likely through modulating MVBs-mediated vesicular trafficking in rice.