Development and Validation of the LC–MS/MS Method for Determination of 130 Natural and Synthetic Cannabinoids in Cannabis Oil

Dietary supplements are widely available products used by millions of people around the world. Unfortunately, the procedure of adding pharmaceutical and psychoactive substances has recently been observed, in order to increase the effectiveness of supplements in the form of hemp oils. For this reason, it is extremely important to develop analytical methods for the detection of substances prohibited in dietary supplements and food products. In the present study, using the LC–MS/MS technique, an innovative method for the detection and quantification of 117 synthetic cannabinoids and 13 natural cannabinoids in dietary supplements and food products in the form of oils during one 13-min chromatographic run was developed. Each method was fully validated by characterization of the following parameters: The limit of detection was set to 0.1 ng/mL (100 µg/g, 0.01%). The limit of quantification ranged from 0.05 ng/mL to 50 ng/mL. The criteria assumed for systematic error caused by methodological bias (±20%) resulting from the recovery of analytes after the extraction process, as well as the coefficient of variation (CV) (≤20%), were met for all 130 tested compounds. The positive results of the validation confirmed that the developed methods met the requirements related to the adequacy of their application in a given scope. Additionally, methods developed using the LC–MS/MS technique were verified via proficiency tests. The developed analytical procedure was successfully used in the analysis of hemp oils and capsules containing them in the studied dietary supplements.     

Behavior of PNIPAM Microgels in Different Organic Solvents

In this research, we studied, in detail, the behavior of common PNIPAM microgels, obtained through surfactant-free precipitation polymerization, in a number of organic solvents. We showed that many of the selected solvents serve as good solvents for the PNIPAM microgels and that the size and architecture of the microgels depend on the solvent chosen. Expanding the range of solvents used for PNIPAM microgel incubation greatly enhances the possible routes for microparticle functionalization and modification, as well as the encapsulation of water-insoluble species. In this demonstration, we successfully encapsulated water-insoluble Sudan III dye in PNIPAM microgels and prepared the aqueous dispersions of such composite-colored microparticles.     

含蜡原油胶凝过程特性研究

利用RS75流变仪在小振幅振荡剪切的模式下分别研究了3种不同历史条件下含蜡原油的胶凝过程, 同时通过偏光显微镜观察了不同降温速率条件下原油中的蜡晶形貌. 结果表明, 在静态降温条件下, 降温速率越大, 原油胶凝的温度越低, 原油形成的胶凝结构越弱; 并且降温速率越大, 原油在恒温静止过程中, 结构随时间恢复的速率越大, 恢复至平衡所需时间越长, 但最终的平衡结构却越弱; 在同样的降温速率下, 原油低温胶凝结构随着降温过程中剪切作用的增强而减弱, 但当历史剪切速率超过一定数值时, 原油的胶凝结构将基本不再继续变化; 在同样的历史剪切速率下, 降温速率越大, 原油在低温(31 ℃)静止初始的储能模量越小, 但最终的平衡结构却越强.     

Oil-in-Water Nanoemulsion Can Modulate the Fermentation,Fatty Acid Accumulation,and the Microbial Population in Rumen Batch Cultures

In this study, three oil-in-water nanoemulsions were tested in two stages: In the first stage, three levels (on the substrate dry matter (DM)), namely 3%, 6%, and 9%, of three different oils, olive oil (OO), corn oil (CO), and linseed oil (LO), in raw and nanoemulsified (N) forms were used separately in three consecutive rumen batch cultures trials. The second stage, which was based on the first stage’s results, consisted of a batch culture trial that compared the raw and nanoemulsified (N) forms of all three oils together, provided at 3% of the DM. In the first stage, NOO, NCO, and NLO preserved higher unsaturated fatty acid (UFA) and less saturated fatty acid (SFA) compared to OO, CO, and LO, respectively; noticeably, NCO had UFA:SFA = 1.01, 1.16, and 1.34 compared to CO, which had UFA:SFA = 0.66, 0.69, and 0.72 when supplemented at 3%, 6%, 9% of DM, respectively. In the second stage, UFA:SFA = 1.04, 1.12, and 1.07 for NOO, NCO, NLO, as compared to UFA:SFA = 0.69, 0.68, and 0.72 for OO, CO, and LO supplemented at 3% of DM. In conclusion, oil-in-water nanoemulsions showed an ability to decrease the transformation of UFA to SFA in the biohydrogenation environment without affecting the rumen microorganisms.     

一种油介质开关振荡器研究

为了产生较高中心频率宽带高功率微波, 对一种填充变压器油作为绝缘介质的1/4波长开关振荡器进行了研究。首先对这种开关振荡器特性阻抗分布进行了分析;然后利用静态电场仿真结果和变压器油击穿实验数据, 分析了该振荡器的耐压能力;在此基础上, 利用CST软件对其瞬态工作特性进行了仿真, 考察了开关间隙击穿位置和间隙电压下降时间对产生阻尼正弦信号的峰值和频率的影响;最后介绍了该振荡器以一种方向系数为3的短螺旋天线作为辐射天线的实验测试结果, 结果表明, 该开关振荡器充电电压上升时间为15 ns时, 耐压达到-322 kV, 产生宽带高功率微波中心频率约360 MHz, 3 dB带宽约22%, 辐射因子170 kV。     

Fabrication of Ti2SnC-MAX Phase Blended PES Membranes with Improved Hydrophilicity and Antifouling Properties for Oil/Water Separation

In this research work, the Ti₂SnC MAX phase (MP) was synthesized via the reactive sintering procedure. The layered and crystalline structure of this MP was verified by SEM, HRTEM, and XRD analyses. This nano-additive was used for improvement of different features of the polyethersulfone (PES) polymeric membranes. The blended membranes containing diverse quantities of the MP (0–1 wt%) were fabricated by a non-solvent-induced phase inversion method. The asymmetric structure of the membranes with small holes in the top layer and coarse finger-like holes and macro-voids in the sublayer was observed by applying SEM analysis. The improvement of the membrane’s hydrophilicity was verified via reducing the contact angle of the membranes from 63.38° to 49.77° (for bare and optimum membranes, respectively). Additionally, in the presence of 0.5 wt% MP, the pure water flux increased from 286 h to 355 L/m² h. The average roughness of this membrane increased in comparison with the bare membrane, which shows the increase in the filtration-available area. The high separation efficiency of the oil/water emulsion (80%) with an improved flux recovery ratio of 65% was illustrated by the optimum blended membrane.     

碱液萃取前后原油中酸性化合物组成的高分辨质谱分析

采用改进的碱液萃取方法分离杜巴原油中的酸性化合物(主要是环烷酸),通过高分辨质谱分析萃取过程中不同组分酸性化合物组成,以研究碱萃取前后酸性化合物的分布与组成特征。实验结果表明,电喷雾傅立叶变换离子回旋共振高分辨质谱(ESI-FT-ICR-MS)是分析原油中酸性化合物的强有力的手段;酸性化合物分布于碱萃取前后的各个组分中,但其组成有明显的差异,碱液萃取出的石油酸主要是相对分子质量小于500的酸性组分,增加反萃取溶剂的用量和极性有利于脱除萃取物中的非碱性氮化合物,对石油羧酸的组成影响不大。     

HPLC法测定辣椒油中苏丹红染料的测量不确定度评定

建立了HPLC法分析辣椒油中苏丹红染料的不确定度模型,分析了方法中的不确定度分量及其来源,计算了各不确定度分量和合成标准不确定度。     

佩兰挥发性化学成分的固相微萃取研究

采用固相微萃取-气相色谱-质谱法分析佩兰中挥发性化学成分,共分离出84个组分,并鉴定了67个组分,用归一化法测定其质量分数,占总挥发性组分峰面积的98.05%。主要成分是对-伞花烃(5.19%)、芳樟醇(3.72%)、β-石竹烯(12.35%)、α-律草烯(13.39%)、α-姜黄烯(2.11%)、(-)-石竹烯氧化物(8.25%)、. /-.-4-乙酰基-1-甲基环己烯(8.91%)。