Ce/Zr/Al类水滑石的合成、表征及其吸附性能研究

本研究对Ce/Zr/Al三元类水滑石材料去除微囊藻毒素(MC)的潜在应用进行了探索。采用共沉淀法合成了碳酸根型Ce/Zr/Al三元类水滑石,通过XRD、IR等手段对样品进行了测试和表征。合成的类水滑石用于吸附MC,并详细研究了其对MC的吸附性能。结果显示,控制反应条件为温度80℃,M3+/M4+摩尔投料比为1∶1,pH为8.5,合成的Ce/Zr/Al三元类水滑石对MC具有较高的吸附性能,对微囊藻毒素LR(MC-LR)最大吸附量可达178μg/g,对MC-LR和微囊藻毒素RR(MC-RR)的吸附效率均大于70%,吸附性能明显高于硅胶等常用吸附剂。这些研究数据表明Ce/Zr/Al三元类水滑石对去除水体中微囊藻毒素具有潜在的应用价值。     

液相色谱-串联质谱法测定粮谷中的伏马毒素

建立了液相色谱-串联质谱同时测定玉米、小麦、大米和黄豆中伏马毒素FB1、FB2的分析方法。样品经甲醇-水-乙酸(74∶25∶1)提取,强阴离子交换柱(SAX)净化后,以0.1%乙酸水溶液-乙腈为流动相,ZORBAX Extend-C18反相色谱柱(150 mm×2.1 mm,1.8μm)进行色谱分离,在电喷雾正离子化模式下,选择反应监测(SRM)方式进行测定。结果表明:FB1和FB2分别在2.5~1 000、5.0~1 000μg/L范围内线性关系良好,相关系数分别为0.999 5和0.999 7。对4种空白基质分别进行0.02、0.50、2.00 mg/kg 3个水平的加标回收实验,FB1和FB2的加标回收率分别为67.5%~90.5%和70.5%~95.3%,相对标准偏差(RSD)分别为1.3%~11.4%和1.5%~10.6%,检出限分别为2.00μg/kg和4.00μg/kg。该方法稳定、可靠,适用于谷物中FB1和FB2的同时检测与确证。     

乳及乳制品中黄曲霉毒素B_1、M_1测定方法改进

建立了一种检测乳及乳制品中黄曲霉毒素B1、M1的高效液相色谱-荧光检测(HPLC-FD)方法。样品经60%乙腈溶液提取,自制固相萃取柱净化,流出液经正己烷、三氟乙酸衍生后荧光检测器检测。考察了填料、柱容量、取样量、提取溶液和流速等对检测的影响,优化了实验条件。结果表明,黄曲霉毒素B1、M1的检测线性范围为0.40~100μg/L,线性系数为0.9991~0.9998,方法检出限为0.050μg/kg。对样品进行0.40、1.0和15μg/L 3种浓度水平的加标回收实验,回收率为53%~105%,相对标准偏差为2.6%~5.1%。该方法操作简单、灵敏度高、准确度好,可用于乳及乳制品中黄曲霉毒素B1、M1的测定。     

Eremophilane sesquiterenes from the marine fungus Penicillium sp. BL27-2

Six eremophilane sesquiterpenes were obtained from a marine fungus Penicillium sp. BL27-2. Their structures were elucidated as 3-acetyl-9, 7 （11）-dien-7a-hydroxy-8-oxoeremophilane （1）, 3-acetyl-13-deoxyphomenone （2）, Sporogen-AO 1 （3）, 7-hydro- xypetasol （4）, 8a-hydroxy-13-deo -xyphomenone （5） and 6-dehydropetasol （6） based on detailed NMR analysis. 1 was a new compound and 2 was obtained as a new natural compound. These compounds were assayed for their cytotoxic activity on P388, A549, HL60, BEL7402 and K562 cell lines by the MTT method. The assay results suggested the epoxide rings in eremophilane molecules were essential for their activity, and acetylation could enhance their activity.     

Flavonoid triglycosides from the seeds of Camellia oleifera Abel

Two flavonoid triglycosides, kaempferol 3-O-{ β-D-glucopyranosyl-（1→2）-[α-L-rhamnopyranosyl-（1→ 6）]-β-D-glucopyranoside} （1） and kaempferol 3-O-{ β-D-xylopyranosyl-（1 → 2）-[α-L-rhamnopyranosyl-（1→6）]-β-D-glucopyranoside } （2）, were isolated from the seed of Camellia oleifera Abel. The absolute configuration of compound 1 was established on the basis of its X-ray analysis. Their cytotoxic activities and anti-HIV-RT activities were evaluated.     

An electrochemical aptasensor based on cu2+-induced signal amplification strategy for the detection of ochratoxin aEI北大核心CSCD

A novel electrochemical aptasensor based on a Cu2+-induced signal amplification strategy was constructed for the rapid, sensitive and specific detection of ochratoxin A （OTA）. The OTA aptamer with poly （T） was hybridized with the captured DNA probe on the electrode surface. In the presence of Cu2+ and ascorbic acid, the end of poly（T） was used as a template to in situ grow copper nanoclusters （Cu NCs）. In the absence of targeted OTA, the gold electrodes after decorating Cu NCs were immersed into an acidic environment to release Cu2+. After enriching Cu2+ at a potential of − 1.6 V, the strongest current value of copper was recorded by measuring differential pulse voltammetry （DPV）. In the presence of OTA, the OTA aptamer was tightly bound to the target OTA. The OTA aptamer broke away from the electrode to reduce the growth of Cu NCs, resulting in lower DPV current response. This proposed method was employed to detect OTA with linear range from 0.1 to 50.0 ng/mL, and the detection limit was 41.2 pg/mL. The Cu2+-induced electrochemical aptasensor can be further applied in the analysis of target OTA in coffee solution samples. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Fe_3O_4@NiSiO_3对水中痕量微囊藻毒素的萃取

通过水热合成法和溶胶凝胶法制备Fe_3O_4@NiSiO_3磁性纳米粒子,该纳米粒子微球具有均一的形貌、良好的磁性和分散性。将合成的Fe_3O_4@NiSiO_3磁性纳米粒子作为磁性固相萃取(MSPE)介质,并结合高效液相色谱(HPLC)建立了水样中痕量微囊藻毒素MC-LR的分析方法。在优化实验条件下,方法在0.25~146.5μg/L浓度范围内呈良好的线性关系,相关系数(r)为0.999 1,检出限为0.011μg/L。将该方法用于纯水中微囊藻毒素的分析,回收率为81.0%,对实际水样的回收率为66.7%~72.0%。表明Fe_3O_4@NiSiO_3磁性纳米粒子具有良好的选择性富集能力,可用于水中痕量微囊藻毒素的萃取。     

超高效液相色谱-串联质谱法测定水华样品中微囊藻毒素及其基质效应的消除

超高效液相色谱-串联质谱法(UPLC-MS/MS)由于其快速、简便的特点,目前广泛应用于水中微囊藻毒素的测定。由于蓝藻水华样品基质比较复杂,UPLC-MS/MS在复杂基质的分析过程中容易发生基质效应问题,严重影响其定量分析结果的准确性。通过稀释样品、优化梯度洗脱程序、减少进样量等方法有效地降低或消除了基质干扰及基质效应问题。7种目标物在各自线性范围内线性关系良好,相关系数(r2)≥0.99;检出限和定量限分别为0.064~0.103μg/L和0.213~0.343μg/L。通过稀释样品、减少进样量等措施,成功测定了水华爆发时实际样品中的微囊藻毒素,并有效降低了基质效应的干扰。该法为微囊藻毒素的准确测定提供一定的参考,对保障饮用水源地的安全具有十分重要的意义。     

高效液相色谱-串联质谱法同时测定饲料中11种霉菌毒素

建立了高效液相色谱-串联质谱(HPLC-MS/MS)同时检测饲料中11种霉菌毒素的分析方法。样品经乙腈提取,MycoSep 228多功能净化柱填料和PRIME HLB固相萃取柱净化;采用Agilent Zorbax SB-C18色谱柱(150 mm×2.1 mm,3.5μm)分离,以甲醇和5 mmol/L乙酸铵水溶液(含0.1%(v/v)甲酸)为流动相梯度洗脱;采用ESI源正、负离子同时扫描,多反应监测(MRM)模式测定,内标法定量。结果表明,11种目标物在各自的线性范围内线性关系良好,相关系数均大于0.99,定量限为2.0~50.0μg/kg。11种霉菌毒素在3个加标水平(1、2、5倍定量限)下的平均回收率为79.3%~101.6%,相对标准偏差(RSD)为5.9%~13.2%(n=5)。该法简单快速,净化效果好,灵敏度高,适用于饲料中11种霉菌毒素的分析。     

高效液相色谱-串联质谱法测定不同畜禽配合饲料中伏马毒素的含量

为摸清复杂基质中FB1和FB2污染的准确水平,本研究建立了高效液相色谱-串联质谱法( LC-MS/MS)测定不同畜禽配合饲料中伏马毒素B1(FB1)和B2(FB2)的分析方法。样品用乙腈-水(50：50, V/V)提取, MAX强阴离子固相萃取柱富集净化后,以0.1%甲酸和甲醇为流动相,经 Thermo C18色谱柱(100 mm ×2.1 mm,5μm)分离,采用电喷雾正电离(ESI+)多反应模式(MRM)监测,外标法定量。结果表明：不同饲料样品中FB1和FB2在1~500μg/kg之间线性关系良好,相关系数(R2)均大于0.9990,定量限分别为0.098和0.197μg/kg,检出限分别为0.328和0.656μg/kg;低、中、高浓度加标回收率为89.7%~95.1%,相对标准偏差(RSD)为3.2%~8.6%。用本方法对市场上采集的106份不同畜禽配合饲料中FB1和FB2含量进行测定,样品检出率为98.11%。本方法适用于基质复杂的畜禽配合饲料中伏马毒素FB1和FB2的准确、快速定性与定量分析。