[Simultaneous determination of eight organic amines in desulfurization solution by ion chromatography].

The applications of organic-amine desulfurization have steadily increased owing to its high efficiency, low cost, and low energy consumption. Different proportions of organic amines exert different effects on sulfur dioxide removal. Therefore, the accurate determination of different organic amines in the desulfurization solution is of great importance. The ion-chromatographic method for the detection of organic amines does not require a derivatization step, has simple pretreatment procedures, and allows for the simultaneous determination of many types of organic amines. In this study, a method based on ion chromatography was developed for the simultaneous determination of ethanolamine (MEA), diethylethanolamine (DEEA), n-methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP), hydroxyethylethylenediamine (AEEA), piperazine (PZ), n-hydroxyethylpiperazine (HEPZ), and diethylenetriamine (DETA). The separation efficiency of the eight organic amines in different types of columns, leaching solutions, and column temperatures were compared. The determination was performed using an IonPac CS17 column with column temperature of 35 ℃ and gradient leaching with methyl sulfonic acid (MSA) solution via the inhibition conductance method. Samples of the desulfurization solution were analyzed using ultrapure water filtered through a 0.22 µm nylon microporous filter membrane and an OnGuard Ⅱ RP column; thus, the pretreatment steps are simple. The eight organic amines showed a good linear relationship within a certain concentration range, and the coefficient of determinations (R2) were greater than 0.998. The limits of detection (LODs) and quantification (LOQs) were determined from the mass concentrations of the organic amines corresponding to signal-to-noise ratios (S/N) of 3 and 10, respectively. LODs of 0.02-0.08 mg/L and LOQs of 0.07-0.27 mg/L were determined from a 1.0 µL sample injection. The actual recoveries ranged from 93.0% to 111%, and the relative standard deviations (RSDs, n=5) ranged from 0.31% to 1.2%. The results indicated that the proposed method has good accuracy and precision; thus, it is suitable for the determination of various organic amines in desulfurization solution.

[Determination of fluoroacetic acid in human blood and urine by accelerated solvent extraction-ion chromatography-mass spectrometry].

Fluoroacetic acid is a highly polar poison used for rodent control. When ingested by the human body, it seriously damages nerve cells and heart tissues and even causes death by cardiac arrest or respiratory failure. Common detection methods for fluoroacetic acid include gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry, both of which require complex pretreatment methods, such as derivatization. In this study, a method to determine fluoroacetic acid in human blood and urine based on accelerated solvent extraction-ion chromatography-mass spectrometry (ASE-IC-MS) was established. Two pretreatment methods, namely, acetonitrile precipitation and accelerated solvent extraction, were compared. Furthermore, the effects of different extraction conditions, such as the extraction time, extraction temperature, and number of cycles, were investigated. The most suitable chromatographic separation conditions, such as the chromatographic column, column temperature, and elution procedure, were determined, and the MS conditions, such as the collision energy (CE) and declustering potential (DP) of the ion pairs of the target compound, were investigated. Based on the experimental results, the optimal pretreatment methods and detection conditions were obtained, and reliable data were collected. Deionized water was used as the extraction solvent, and blood and urine samples were processed by accelerated solvent extractor. The supernatant was sequentially collected via centrifugal ultrafiltration and 0.22 µm membrane filtration, diluted 50 times, and then injected into the chromatographic column for detection. An Ion Pac AS20 IC column was used for isocratic elution with 15.0 mmol/L KOH solution as the eluent. The effluent was passed through a suppressor and into a triple quadrupole mass spectrometer, which was used to perform MS/MS (ESI-) in multiple reaction monitoring (MRM) mode. The quantitative ion was m/z 77.0>57.0 when the CE and DP were -15.0 eV and -20.0 V, respectively. An external standard method was used for quantitative analysis. The results showed a good linear relationship for fluoroacetic acid in the range of 0.5-500.0 µg/L (r>0.999), with limits of detection (LOD) and quantification (LOQ) of 0.14 and 0.47 µg/L, respectively. The recoveries of fluoroacetic acid in blood and urine were 93.4%-95.8% and 96.2%-98.4%, respectively. The intra-day RSDs for blood and urine were 0.8%-1.6% and 0.2%-1.0%, respectively, while the inter-day RSDs were 2.3%-3.8% and 3.9%-6.9%, respectively. Further investigation revealed that the matrix effects of this method in blood and urine, at -7.4% and -3.0%, respectively, were fairly weak. The established method was successfully applied to detect fluoroacetic acid in human blood and urine obtained from a poisoning case, and the results obtained provided crucial clues that led to swift case resolution. The efficiency of the method was significantly higher than that of conventional detection methods. In conclusion, the developed method has high sensitivity and good repeatability and is suitable for the rapid detection of fluoroacetic acid in human blood and urine. Moreover, because this method does not require derivatization, it is simple and efficient.

CD11c+DCs promote the occurrence and development of psoriasis-like morbidity in K14-VEGF transgenic mice / 基础医学与临床

Objective To investigate the auxoaction and mechanism of CDllc+DCs on psoriasis. Methods CDllc+ DCs in the psoriasis-like lesions were confirmed by immunofluorescence double staining experiments. The CD1lc+ DCs were subcutaneously injected into the neck skin of transgenic mice without disease. The clinical features were observed and assessed with PASI score every day. The ear and back skin were checked by HE stained. At the same time, the T lymphocyte and DCs of bone marrow, spleen, submandibular lymph nodes and blood were analyzed by flow cytometry, and the T lymphocyte in the skin lesions were analyzed by immunofluorescence. The heart, liver, spleen, lungs and kindey were HE stained. Results In the psoriasis-like lesions, about 90％ CDllc+ cells expressed CDllc. HE test showed that the thickness of the skin layer was significant different between the experimental group (ear: 29±4 μm; back: 25±3 μm) and the control group(ear: 11±2 μm; back: 9±1 μm) (P＜0.01). CD3 + CD4+ T lymphocyte cells in the blood of the experimental mice (17.87％) were decreased significantly (P＜0.01) compared with the control group mice (31.77％). The numbers of Thl and Th17 cells from bone marrow, spleen, submaxillary lymph nodes and blood, as the same as CD1lc+DCs from bone marrow and submaxillary lymph nodes, were decreased in the experimental mice compared with the control group mice (P＜0.01). The number of CD4﹢T cells, CD8+T cells, IL-17a+cells and IFN-γ+cells in the skin lesions from the experimental group all were higher than that from the control group (P＜0.01). And the vessels in the lesions of the experimental group were higher than that in the control group (P＜0.01). Conclusions CD1 lc+CD1 lc+DCs may play an important role in the occurrence and development of psoriasis by increasing the T lymphocyte and the blood vessel in the skins of K14-VEGF transgenic mice.

A new trincallane derivative from Salacia hainanensis Chun et How / 药学学报

Chemical constituents of the roots and stem of Salacia hainanensis Chun et How were isolated and purified with column chromatography on silica gel, Sephadex LH-20 and preparative HPLC. Their structures were elucidated based on physicochemical and spectral spectroscopic analysis. Depending on the activities of anti-alpha-glucosidase and inhibiting AGEs (advanced glycation end products, AGEs) formation in vitro, nine compounds were identified as 26, 27-dihydroxy-7, 24-tirucalladien-3-one (1), abruslactone A (2), lupeol (3), 21alpha, 30-dihydroxy-D: A-friedooleanan-3-one (4), 15alpha-hydroxyfriedelan-3-one (5), friedelin (6), mangiferin (7), epicatechin (8) and beta-sitosterol (9), separately. Among them, compound 1 is a new compound, and compound 2 was isolated from the Salacia genus for the first time, while, compounds 3, 4, 5, 8 were obtained from this plant for the first time.