HPLC determination

  • 文章类型: Journal Article
    存在的阿奇霉素的光降解是在紫外线照射下使用H2O2在水中进行的。在这项研究中考虑的反应变量是H2O2溶液的量和阿奇霉素的初始浓度,以评估光降解过程的性能。在搅拌20分钟期间,在黑暗中未观察到阿奇霉素降解。研究表明,在紫外线照射下,使用H2O2作为氧化剂可以有效地光降解阿奇霉素。辐照溶液的pH值显着改变了阿奇霉素的降解。在酸性pH下降解较低,并且随着pH变为碱性而显示出增加的趋势。随着H2O2的量增加(浓度增加),阿奇霉素的降解增加。随着反应溶液中阿奇霉素的浓度升高,阿奇霉素的降解降低。使用含有3mLH2O2的1.0ppmAZT溶液在1小时内实现了AZT的最高降解。获得的实验数据很好地拟合了零级反应动力学。发现这项研究的结果非常出色。与文献中报道的相比,它们在1小时内显示出100%的降解,使用纳米材料进行光催化和使用光辐射和/或H2O2进行光解。发现UV/H2O2系统对阿奇霉素的光降解非常有效,该系统可用于降解工业废水中存在的其他有机污染物。
    The photodegradation of azithromycin present was carried out in water using H2O2 under UV irradiation. The reaction variables considered in this study were the amount of H2O2 solution and the initial concentration of azithromycin to evaluate the performance of the photodegradation process. The azithromycin degradation was not observed in the dark during stirring for 20 min. The study showed an efficient photodegradation of azithromycin using H2O2 as an oxidant in the presence of UV irradiation. The azithromycin degradation was altered significantly by the pH of the irradiated solution. The degradation was low at an acidic pH and showed an increasing trend as the pH changed to basic. The azithromycin degradation increased with a higher amount (higher concentration) of H2O2. The degradation of azithromycin decreased with a higher concentration of azithromycin in the reacting solution. The highest degradation of AZT was achieved in 1 h using a 1.0 ppm AZT solution containing 3 mL of H2O2. The experimental data obtained were well-fitted to zero-order reaction kinetics. The results of this study were found quite excellent. They showed 100% degradation in 1 h when compared with those reported in the literature, both with photocatalysis using nanomaterials and photolysis using light irradiation and/or H2O2. The UV/H2O2 system was found to be quite efficient for the photodegradation of azithromycin, and this system can be applied to degrade other organic pollutants present in industrial wastewater.
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  • 文章类型: Journal Article
    α-DCs(α-二羰基)已被证明与衰老和许多慢性疾病的发生和发展密切相关。这类成分在各种食品和饮料中的广泛存在已被明确确定,但是它们在各种植物药中的出现仍然默默无闻。在这项研究中,我们建立并评估了HPLC-UV方法,并将其用于测量包括3-脱氧葡萄糖酮(3-DG)在内的四种α-DC的含量,乙二醛(GO),甲基乙二醛(MGO),和35种中草药中的二乙酰(DA)用4-硝基-1,2-苯二胺衍生化。结果发现3-DG是α-DC中的主要成分,在所有选定的草药中都可检测到,浓度范围从高良姜种子中的22.80μg/g到西兰果实中的7032.75μg/g。其它三种化合物的含量远低于3-DG,GO高达22.65μg/g,MGO高达55.50μg/g,和DA至18.75μg/g,分别。数据显示,草药中总共四种α-DC的含量通常与各种食物中的含量相当,这意味着,鉴于α-DCs,草药可能对人类健康有潜在风险。
    α-DCs (α-dicarbonyls) have been proven to be closely related to aging and the onset and development of many chronic diseases. The wide presence of this kind of components in various foods and beverages has been unambiguously determined, but their occurrence in various phytomedicines remains in obscurity. In this study, we established and evaluated an HPLC-UV method and used it to measure the contents of four α-DCs including 3-deoxyglucosone (3-DG), glyoxal (GO), methylglyoxal (MGO), and diacetyl (DA) in 35 Chinese herbs after they have been derivatized with 4-nitro-1,2-phenylenediamine. The results uncover that 3-DG is the major component among the α-DCs, being detectable in all the selected herbs in concentrations ranging from 22.80 μg/g in the seeds of Alpinia katsumadai to 7032.75 μg/g in the fruit of Siraitia grosuenorii. The contents of the other three compounds are much lower than those of 3-DG, with GO being up to 22.65 μg/g, MGO being up to 55.50 μg/g, and DA to 18.75 μg/g, respectively. The data show as well the contents of the total four α-DCs in the herbs are generally in a comparable level to those in various foods, implying that herb medicines may have potential risks on human heath in view of the α-DCs.
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  • 文章类型: Journal Article
    已开发出一种简单的HPLC法测定血液中抗血小板药物替格瑞洛的方法。研究并优化了样品制备和提取条件。通过使用高氯酸的蛋白质沉淀法研究了血浆的制备,甲醇,乙腈和三氟乙酸。发现用乙腈沉淀蛋白质是最合适的。替格瑞洛的色谱分离在C18柱上进行,流动相由乙腈和在pH8.0缓冲的15mM乙酸铵组成。该方法用于测定心脏病发作患者血浆中的替格瑞洛。在施用初始负荷剂量的抗血小板药物后1.5小时收集血样。替格瑞洛的平均浓度为0.97±0.53μg/mL。开发的方法被证明是非常有选择性的,没有其他内源性物质的干扰和可能的共同给药的影响。实际样品中通过信噪比估计的检测限和定量限分别为0.24μg/mL和0.4μg/mL。所开发的方法简单,在心脏病发作的最初几个小时内服用初始负荷剂量的替格瑞洛后,可以轻松地应用于临床状况和紧急心脏情况。
    A simple HPLC method was developed for the determination of antiplatelet drug ticagrelor (TCG) in blood. Sample preparation and extraction conditions were investigated and optimized. The preparation of blood plasma was investigated by protein precipitation using perchloric acid, methanol, acetonitrile (ACN), and trifluoroacetic acid. Protein precipitation using ACN was found to be the most suitable. Chromatographic separation of TCG was performed on a C18 column with a mobile phase consisting of ACN and 15 mM ammonium acetate buffered at pH 8.0. The method was applied to determine TCG in blood plasma of patients who had a heart attack. Blood samples were collected 1.5 h after the administration of the initial loading dose of the antiplatelet drug. The average concentration of TCG was found to be 0.97 ± 0.53 μg/ml. The developed method proved to be very selective, without interferences from other endogenous substances and the influences of possible coadministered drugs. The limits of detection and quantification estimated by the signal-to-noise ratio in real samples were 0.24 and 0.4 μg/ml, respectively. The developed method is simple and can be easily applied in clinics and emergency cardiac situations after the initial loading dose of TCG in the first few hours of a heart attack.
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  • 文章类型: Journal Article
    The fermentation product of Cordyceps sinensis mycelium Cs-4 was commonly used as alternative substitutes of natural C. sinensis. Massoia lactone is the dominant component in the volatile oil of Cs-4 mycelium. In this research, we present a high performance liquid chromatography (HPLC) method for the quantitation of massoia lactone in Cs-4 mycelium. The high and stable contents of massoia lactone with values of 2.98-3.77 mg/g, indicated that massoia lactone could be considered as a marker for the quality assessment of this product. The results of MTT and CCK-8 assay showed that Cs-4 mycelium volatiles exhibited cytotoxicity against eight malignant tumor cells (IC50  = 6.0-49.8 μg/ml) in comparison to the anticancer drug 5-fluorouracil (IC50  = 17.0-425.3 μg/ml), and massoia lactone might be the chemical basis for the anticancer effects of Cs-4 mycelium. Compared to the commercial drugs paclitaxel and docetaxel (IC50  = 253-1973 μg/ml), the Cs-4 mycelium volatiles and massoia lactone were discovered to possess inhibitory to taxol-resistant cell lines (IC50  = 1.5-8.6 μg/ml). PRACTICAL APPLICATIONS: Considering that there is still a lack of marker components distinctive to Cs-4 mycelium, the HPLC method represents a useful tool for the quality evaluation of Cs-4 mycelium. Moreover, the volatile oil of Cs-4 mycelium and massoia lactone have prominent anticancer property in vitro. It gives a clue that Cs-4 mycelium, the volatile oil and massoia lactone could be potentially employed in the food and medical industries for its anticancer applications.
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  • 文章类型: Comparative Study
    A comparative study on the extraction efficiency of five non-steroidal anti-inflammatories was carried out using three different electromembrane extraction (EME) devices with different geometries. The employed setups were (a) a hollow fiber configuration (HF-EME), (b) a microfluidic device that allows working in semi-dynamic mode (μF-EME), and (c) a static miniaturized flat membrane device (FM-EME). Each system was applied to the extraction of salicylic acid (SAC), ketoprofen (KTP), naproxen (NAX), diclofenac (DIC), and ibuprofen (IBU) and subsequent determination by high-performance liquid chromatography with UV and fluorescence detection (HPLC/UV-DAD-FLD). Voltage, pH composition, and extraction time were optimized for all devices. Additionally, volume ratio was investigated for HF-EME and FM-EME and flow rate for the microfluidic device. HF-EME provides the best result in terms of sensitivity with a limit of detection (LOD) between 0.1 and 1.5 ng mL-1 for SAC and KTP, respectively, while LODs for μF-EME were between 100 ng mL-1 and 400 ng mL-1 for SAC and DIC, respectively; however, a lower amount of sample was required. Finally, the obtained results, in terms of enrichment factors and extraction recoveries, were discussed to establish the advantages and disadvantages of each device. The proposed EME methods were successfully applied to the determination of the target analytes in fortified human urine samples. Graphical abstract.
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  • 文章类型: Journal Article
    Velvet antler (VA) is crucial and precious nourishment in China and some countries in Southeast Asia and has excellent anti-fatigue effect. The incidence of fatigue syndrome has increased gradually. VA can be a potential source of anti-fatigue products. Therefore, we investigated the anti-fatigue activity of different sections (upper, middle, and basal section) of VA from different species (red deer and sika deer) via loading swimming test in mice. Furthermore, nucleosides are one kind of active components in VA which could considerably reduce fatigue in mice. In order to explore whether the nucleosides are correlated with anti-fatigue effect, the contents of eight nucleosides (uracil, cytidine, hypoxanthine, xanthine, thymine, inosine, guanosine, and adenosine) were determined simultaneously using high-performance liquid chromatography. The results indicated that the swimming time in mice was increased from basal to upper section, which was consistent with the change trend of the total contents of eight nucleosides of VA. Therefore, we speculated that the contents of nucleosides in VA may affect its anti-fatigue effect. Furthermore, the contents of nucleosides were also used as a reference for evaluating the quality of different parts of VA obtained from red and sika deer.
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  • 文章类型: Journal Article
    Background α-Dicarbonyl compounds (α-DCs) have been detected in body fluids including plasma and urine and elevation of this sort of compounds in vivo has been associated with the development of many kinds of chronic diseases. However whether α-DCs are present in human saliva, and if their presence/absence can be related with various chronic diseases is yet to be determined. Methods In this study, a pre-column derivatization HPLC-UV method was developed to measure 3-deoxyglucosone (3-DG), glyoxal (GO), methylglyoxal (MGO), diacetyl (DA), and pentane-2,3-dione (PD) in human saliva employing 4-(2,3-dimethyl-6-quinoxalinyl)-1,2-benzenediamine (DQB) as a derivatizing reagent. The derivatization of the α-DCs is fast and the conditions are facile. The method was evaluated and the results show that it is suitable for the quantification of α-DCs in human saliva. Results In the measurements of these α-DCs in the saliva of 15 healthy subjects and 23 type 2 diabetes mellitus (T2DM) patients, we found that the concentrations of GO and MGO in the saliva of the diabetic patients were significantly higher than those in healthy subjects. As far as we know, this is the first time that salivary α-DC concentrations have been determined and associated with T2DM. Conclusions The developed method would be useful for the measurement of the salivary α-DC levels and the data acquired could be informative in the early screening for diabetes.
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  • 文章类型: Journal Article
    Verbena carolina L. (Verbenaceae) is used as a decoction in Mexican folk medicine with applications against digestive problems and for dermatological infections. The present work firstly reported HPLC analysis, as well as the free radical scavenging capacity of the extracts and isolated compounds. Antimicrobial analyses of these substances against the bacteria Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Salmonella typhi and the fungi Candida albicans, Trichophyton mentagrophytes and T. rubrum were also tested, as well as the acute oral toxicity in mice of aqueous extracts. Major secondary metabolites in V. carolina extracts were isolated by conventional phytochemical methods which consisted of three terpenoids ((1), (3) and (4)) and four phenolic compounds ((2), (4)-(6)). Their contents were determined by HPLC in six different samples from different locations. The results indicated that ursolic acid (1), hispidulin (2), verbenaline (3), hastatoside (4), verbascoside (5), hispidulin 7-O-β-d-glucuronopyranoside (6) and pectolinaringenin-7-O-α-d-glucuronopyranoside (7) were the main constituents and ranged from 0.17 to 3.37 mg/g of dried plant, with verbascoside being the most abundant and with a significant antioxidant activity in reactive oxygen species (ROS). Hispidulin was the only active compound against T. mentagrophytes and T. rubrum. The aqueous extract showed no significant toxicity (LD50: > 5000 mg/mL). To our knowledge, this is the first comprehensive report of the chemical characterization of V. carolina and also of the activity of its constituents towards reactive oxygen species and dermatophytes, and its safety for consumption.
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  • 文章类型: Journal Article
    Transdermal administration of drugs that penetrate, in this case directly into the blood circulation, has many advantages and is promising for many drugs thanks to its easy application and good patient compliance. (S)-8-Methyl-6,9-diazaspiro[4.5]decan-7,10-dione (alaptide), has been studied as a potential chemical permeation enhancer. Based on its structure, four selected piperazine-2,5-diones were synthesized by means of multi-step synthetic pathways. All the compounds were investigated on their ability to enhance the permeation of the model drug theophylline from the hydrophilic medium propylene glycol:water (1:1). In vitro experiments were performed using vertical Franz diffusion cells at constant temperature 34 ± 0.5 °C and using full-thickness pig (Sus scrofa f. domestica) ear skin. Withdrawn samples were analyzed by RP-HPLC for determination of the permeated amount of theophylline. All the compounds were applied in ratio 1:10 (w/w) relative to the amount of theophylline. One hour after application, the permeated amount of theophylline from formulations with alaptide and (3S,6S)-3,6-dimethylpiperazine-2,5-dione, was ca. 15- and 12-fold higher, respectively, than from the formulation without the tested compounds. Despite the enhancement ratio of both enhancers in a steady state was ca. 2.3, the pseudo-enhancement ratio in the time range from 1 to 3 h was 4.4. These enhancement ratios indicate that the compounds are able to enhance the permeation of agents through the skin; however, the short-term application of both compound formulations seems to be more advantageous. In addition, the screening of the cytotoxicity of all the prepared compounds was performed using three cell lines, and the compounds did not show any significant toxic effect.
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  • 文章类型: Journal Article
    虽然,棒曲霉素和曲霉毒素是由相同属的霉菌产生的,然而,棒曲霉素是苹果汁中研究最广泛的霉菌毒素,尚无报道探讨苹果汁中是否存在OchratoxinA。因此,这项研究的目的是探索沙特阿拉伯吉达市场苹果汁中的Patulin和OchratoxinA的存在。马铃薯葡萄糖琼脂(PDA)用于检测真菌污染。使用配备有设定在276nm的UV检测器的HPLC测定棒曲霉素。此外,将具有荧光检测器的HPLC设定在333和420nm作为激发和发射波长,分别,用于曲霉毒素A的分离。所有苹果汁样品均不含真菌和酵母。在浓度为152.5ppb的17种类型(5.88%)中,仅检测到一种类型的Patulin(PAT),(305%)与最大允许水平(50ppb)相比增加。然而,在17种类型中的5种类型(29.41%)中发现了苹果汁样品中的OchratoxinA(OTA)。OTA的浓度范围为100至200ppb,与允许的限值(20ppb)相比,达到5-10倍。
    Although, Patulin and Ochratoxin are produced by the same genera of molds, however, Patulin was the most extensively studied mycotoxins in apple juice and no reports have explored the presence of Ochratoxin A in the apple juice. Therefore, the objective of this study was to explore the presence of Patulin and Ochratoxin A in apple juice in Saudi Arabian market of Jeddah. Potato dextrose agar(PDA) was used to detect fungal contamination. Patulin was determined using HPLC equipped with a UV detector set at 276 nm. Also, HPLC with fluorescence detector was set at 333 and 420 nm as excitation and emission wavelength, respectively,was used for Ochratoxin A separation. All samples of apple juice were free from fungi and yeasts. The Patulin (PAT) was detected in only one type out of 17 types (5.88%) with a concentration of 152.5 ppb, (305%) increased compared with the maximum permitted level (50 ppb). However the occurrence of Ochratoxin A (OTA) in apple juice samples was discovered in 5 types out of 17 types (29.41%). The concentration of OTA ranged from 100 to 200 ppb reaching 5-10-folds compared with the permissible limits (20 ppb).
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