An automated magnetic bead extraction method for measuring plasma metanephrines and 3-methoxytyramine using liquid chromatography tandem mass spectrometry.

Liquid chromatography tandem mass spectrometry (LC-MS/MS) is used routinely in clinical diagnostics; however, automating the sample pretreatment is challenging. We established and evaluated an automated method based on the magnetic bead extraction principle (MBE) to measure normetanephrine (NMN), metanephrine (MN), and 3-methoxytyramine (3-MT). The target analytes were extracted, purified, and concentrated using different solvents and chemical bond-modified magnetic beads transferred via a magnetic bar. The linearity, recovery, matrix effect, and precision of MBE were evaluated thoroughly, and compared with traditional solid-phase extraction (SPE) using 131 plasma samples. The chromatography peaks of metanephrines and 3-MT, extracted via MBE, are symmetrical, without interfering peaks. The linearity was excellent with correlation coefficient (r) > 0.99. The MBE exhibited good reproducibility with within-run coefficient variations (CVs) of 1.96-2.00%, 4.06-5.75%, and 3.89-4.90% for MN, NMN, and 3-MT, respectively. The total CVs for MN, NMN, and 3-MT were 1.96-2.80%, 5.12-5.75%, and 5.44-6.27%, respectively. The relative recoveries for MN, NMN, and 3-MT varied between 93.5 and 107.4%, whereas their biases were all within 10%. The results for MN, NMN, and 3-MT extracted via MBE compared with SPE exhibited excellent correlation, with r > 0.99; the mean bias% for MN, NMN, and 3-MT were small (-2.9%, -3.2%, and -3.2%, respectively). In conclusion, the automated MBE method for measuring plasma metanephrines and 3-MT can be applied in future routine clinical diagnostics, and the MBE principle may indicate a new era for LC-MS/MS in clinical application.

The effect of microorganisms on the biomodification of montan resin from lignite.

Montan resin (MR) is an industrial by-product or solid waste generated during the production of refined montan wax and is not typically reused. In this paper, a bio-modification method using three strains of microorganisms, Acinetobacter venetianus (AV), Pseudomonas aeruginosa (PA), and Phanerochaete chrysosporium (PC), was studied to promote the performance and bio-function of MR so that MR could be recycled. MR can be degraded by these three microorganisms, and their weight loss rates were similar over the treatment period of 15 days. Compared with the original MR, the hydrophilicity of modified MRs was improved, which was related to the increase in apparent oil-water partition coefficients (Kows) and oxygen-containing and hydrophilic groups in modified MRs based on IR and GC-MS analysis. The bio-function of modified MRs by the three strains in terms of promoting maize seed germination and seedling growth was greater compared with untreated MR. Overall, these findings indicate that biomodified MRs might have useful agriculture applications.Implications: An environmentally-friendly method using microorganisms to achieve recycle of solid waste, montan resin (MR) was established in this study. Through this bio-treatment, the performance and bio-function of MR were both improved, that is the appearance and hydrophilicity of modified MRs were better than thoes in before, and the modified MRs treated by three strains showed the better promoting effects on maize seed germination and seedling growth than untreated MR, indicating the modified MRs have the certain potential of agricultural utilization in the future.

Chemical modification of montan resin by peracetic acid and agricultural application of its modified products.

Montan resin (MR) is a by-product produced during the refinement process of montan wax extracted from lignite and has no usage yet. Chemical modification is an effective method to change the material property for expanding or converting the application area of the material itself. Our previous study found that the high hydrophobicity of MR is the primary limiting factor for its utilization in agriculture. Based on this point, this study attempted to chemically modify MR using the oxidation of peracetic acid, resulting that the MR hydrophilicity was significantly improved, and a water-soluble product (WSP) was obtained. The optimized oxidation conditions of MR, including the reaction temperature (X1), reaction time (X2), weight ratio of oxidant and montan resin (X3), and oxidant concentration (X4), were determined using single-factor experiments and response surface analysis. The modification degree was evaluated using elemental and oil-water partition coefficient analyses, infrared (IR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS), revealing that the oil-water partition coefficient of the modified product decreased and that the number of chemical constituents with oxygen-containing functional groups clearly increased after modification. Furthermore, the WSP was tested its effects on germination and seedling growth of the wheat seed. Compared with the control group, the WSP showed a promoting effect on the growth and germination of wheat. The WSP concentrations of 600 mg·L-1 and 300 mg·L-1 had the most substantial effect on the root and seedling growth of wheat, respectively. Implications: Montan resin, a useless by-product produced from crude montan wax, was chemically modified via oxidation of peracetic acid. Its hydrophilicity was significantly improved, and a water-soluble product was obtained after the chemical modification. The optimized oxidation conditions of montan resin were determined using single-factor experiments and response surface analysis. The amount of chemical constituents with oxygen-containing functional groups increased in the modified products after modification, as determined by IR and GC-MS analysis, among other methods. The water-soluble modified product showed an obvious effect in promoting growth and germination of wheat at 600 mg·L-1 and 300 mg·L-1, respectively.

Biological Modification of Montan Resin from Lignite by Bacillus benzoevorans.

The montan resin (MR) is a solid waste produced during the industrial process of refined montan wax from lignite, and usually disposed by landfill and incineration, which easily cause environmental pollution and resource waste. Based its physicochemical properties, our study attempted to modify MR by Bacillus benzoevorans to achieve ecological utilization of MR. As results, the weight loss rate of MR, expressed as modification degree, was found to increase with the increase of B. benzoevorans-incubated time. The apparent oil-water partition coefficient (Kow), used to evaluate the improvement on hydrophilicity of MR, significantly increased (P < 0.01) after modification. IR analysis showed the functional groups of -OH and C=O in modified MR were more than those in MR. Meanwhile, comparison of the chemical changes between MR and modified MR by relatively quantitative analysis of gas chromatography-mass spectrometry (GC-MS) revealed that the content of some chemical components in the latter decreased, and the newly appeared chemical components all had more oxygen-containing functional groups. The bioactivity of the modified MR in agricultural application was evaluated regarding germination and seedling growth of maize seed preliminarly. Compared with the original MR-treated group, the modified MR showed an obvious effect on promoting the growth and germination of maize.

Rhodium-catalyzed triazole-directed C-H bond functionalization of arenes with diazo compounds.

Heterocyclic compounds bearing 1,2,3-triazole scaffolds have found wide application both in medicinal chemistry and materials science. In this paper, rhodium(iii)-catalyzed triazole-directed alkylation reactions of arenes using diazo compounds as the alkylating agents are described. A number of polysubstituted arenes were provided from easily available materials in good yields under mild conditions. The reactions proceed via triazole-directed ortho C-H bond activation and subsequent carbene insertion originating from diazo compounds.