梅兰妮 Voigt 感谢 Niederrhein 大学 Promotionskolleg 的助学金。作者感谢他们的机构提供进一步的财政支持。

1. 样品制备: 固相萃取
<ol><li>收集大约1升的水为样品的准备。</li>
	<li>在带孔径为2µm 的蓝色波段过滤器上过滤样品以去除粗颗粒。</li>
	<li>用3毫升甲醇和3毫升的超纯水平衡了 SPE 墨盒。</li>
	<li>将滤液 (1 升) 应用于 SPE 碳粉盒上, 用隔膜泵中的适度真空 ( e. g) 增加流速。 注: 多个 SPE 墨盒可以并行运行。</li>
	<li>用3毫升的超纯水冲洗样品。</li>
	<li>洗脱用3毫升的甲醇对碳粉盒中的分析物进行了分析。</li>
	<li>用旋转蒸发器将3毫升的洗脱液浓缩成干燥。</li>
	<li>将残留物溶解在1毫升的超纯水中。</li>
	<li>通过注射器过滤器过滤解决方案, 并将其存储在一小瓶中, 用于非靶向分析的 HPLC-ESI-Q。</li>
</ol>2. 高效液相色谱-ESI-Q-ms 方法进行非靶向和靶向分析, ms/毫秒
<ol><li>将药瓶转移到 HPLC-ESI-Q-autosampler 女士。</li>
	<li>设置所有相关参数 (表 1) 的 HPLC-ESI-Q-毫秒。 注: 如果使用的是有限的碰撞能量, 那么, 碰撞能量 (CE) ≠ 0, 离子将会支离破碎。此模式对应于目标 ms/ms 方法。</li>
	<li>开始测量。</li>
	<li>分析产生的图谱和质谱。</li>
</ol>3. 紫外线照射实验
<ol><li>溶解抗生素化合物,如红霉素 (750 毫克/升), 在纯水中的20毫克/升最终浓度。</li>
	<li>填充1升 photoreactor, 包裹在铝箔, 与750毫升的解决方案。</li>
	<li>介绍给反应堆提供 15 W 功率的灯。</li>
	<li>用 500 rpm 的磁力搅拌器。</li>
	<li>如有必要, 将 pH 值调整为所需值3-4、6-7 或 8-9, 并通过滴状加法 HCl (0.1 米) 或 NH3 (0.1 米)。用 pH 值6-7 作为例子。</li>
	<li>使用注射器将反应溶液的2毫升作为样品, 并将其转移到2毫升玻璃瓶中。</li>
	<li>打开紫外线灯, 跟踪时间的流逝。 注: 辐照时间10分钟通常是充足的。如果需要 photoreaction 的完整性, 则可能需要使用第一个系列的结果记录第二个实验系列。 注意: 紫外线照射可能导致失明。</li>
	<li>每三十年代在第一5分钟内从溶液中抽出2毫升样品。然后, 每六十年代取一个样本, 直到实验结束。把样品转移到2毫升的瓶子里。</li>
	<li>储存瓶直到 HPLC-ESI-Q 飞行-MS 分析在-4 °c。</li>
	<li>用液相色谱-ESI-Q-毫秒-MS 分析16个样品, 并以步骤2中描述的方法。</li>
</ol>4. 动力学分析
<ol><li>准备合适的软件, 如 MATLAB R2016b 的曲线拟合工具箱。</li>
	<li>根据一阶动力学的结果, 拟合出光致母抗生素化合物降解的质量区域与时间数据, 见 eq. 242,43 <img alt="Equation 1" src="/files/ftp_upload/57434/57434eq1.jpg">(2) 浓度<img alt="Equation 2" src="/files/ftp_upload/57434/57434eq2.jpg">指的初始浓度 educt a, ca 到实际浓度在反应时间t与速率常数k1从第一反应步骤 A 到 B。</li>
	<li>配合 degradates 的质量区域与时间曲线使用 eq. 3 和 4, 因为它们可以被描述为一个连续的或后续的后续反应的中间体,我. e., 产品 B 或 C 根据反应模型 a →B → c → D。 <img alt="Equation 3" src="/files/ftp_upload/57434/57434eq3.jpg">(3) <img alt="Equation 4" src="/files/ftp_upload/57434/57434eq4v5.jpg">(4) 浓度cb和 c c是指中间体 b 和 c;和k2,k3到相应的速率常数 B 到 c, c 到 D。</li>
	<li>使用 eq 5 来适应数据, 如果辐照时间不足以观察照片产品的降解。这降解可以被视为最终产品 d 与浓度Cd获得速率常数。 <img alt="Equation 6" src="/files/ftp_upload/57434/57434eq6.jpg">(5)<ol>
<li>用 eq 6 代替 eq 3, 如果反应以 b 为结束, 则计算 b 的浓度。如果 c 是最终产品, 根据 eq 计算 c 的浓度. 7 而不是情商4。 <img alt="Equation 7" src="/files/ftp_upload/57434/57434eq7.jpg">(6) <img alt="Equation 8" src="/files/ftp_upload/57434/57434eq8.jpg">(7)</li>
	</ol>
</li>
	<li>使用 eq 8 为半衰期t1/2的决心。 <img alt="Equation 10" src="/files/ftp_upload/57434/57434eq10.jpg">(8)</li>
</ol>

作者声明没有竞争的财政利益。

本报告中提出的非目标分析的例子表明, 用 HPLC--ESI-Q-毫秒-ms、ms 和对照标准作为最终证明, 对地表水中的药物进行了鉴定。非靶向分析的强度是基于在给定保留时间内的所有离子的检测和高质量精度导致的试探性分子公式的预测。作为一种飞行质量光谱仪的替代品, 对轨道离子阱的应用进行了描述, 用于水44中的污染物分析。以分子公式预测为出发点, 快速选择参考标准。由于只有预先选定的离子通过四极过滤器, Q-ms 仪器的目标 ms 方法的应用允许了特定化合物的检测。在一般的目标分析使用三重四极质谱仪也在水分析45。为了补偿由于仪器缺陷而引起的理论质量偏差, 可以进行与参考标准的色谱比较。还可以选择目标 ms/ms 方法进行识别分析。在这里, 离子被选择, 碎片和他们的碎片检测。由于 ms 的灵敏度低于 ms, 药物在调查水样中的浓度过低, 无法产生有意义的碎片。但是, 如果检测到碎片, 则可以用更高的置信度识别化合物。通过集中一个较大的初始水样体积可以克服灵敏度不足的情况。此外, 由于潜在的生物降解46、47、48、49, 在取样后应尽快进行测量。否则, 样品应储存在-20 °c, 以排除复合降解或反应。
有时, 相同的 m-/z 值出现在不同的保留时间。这可能是由于异构体需要不同的分析技术。也可能发生, 根本没有发现任何化合物, 这不一定证明他们的缺席。它们可能只是不形成离子或发生在检测的极限之下。水的类型也对药物的存在产生影响。与污水处理厂48、50、51、52、53废水相比, 药物很少进入水源和地下水。
在降解实验中, 由于光源的光子通量或光子的照射率对降解和降解机理有很大的贡献, 因此应提前对辐照源进行表征。对于最初的尝试, 一个真空紫外/紫外线灯, 可能是一个低压汞灯是足够的。一般情况下, 加过氧化氢, H2O2,加速降解27,36,37,54。当使用不同的灯, e., 一盏 UVA 灯时, 应确保羟基自由基的形成, 例如, 通过加入二氧化钛23,24,30,31. 对于许多化合物, 如红霉素, oh 基, 而不是药物本身的光反应性,27是降解诱导的物种。
对于动力学参数的确定, 在质量检测的图谱中, 表示浓度的信号区域与辐照时间进行了绘制。为了适应数据, 最好使用合适的软件。在这里, 利用 MATLAB 的曲线拟合工具, 可以用正确的方程快速地计算和拟合数据。中间体的动力学由更加复杂的等式决定。适合的质量参数,我, R2和 RMSE, 也很容易获得。
本文通过对水的分析, 发现和鉴定了超纯水中的药物污染物和红霉素的光降解特性。在环境水体中, 如 humins, 由于光吸收物质, 如表面水, 不同的降解速度和速率常数将得到。根据作者的经验, 退化往往发生得更慢, 但有时在可比率41,56。
世界范围内的药物, 特别是抗生素, 在水生环境中的问题和由此产生的危害仍然持续增长1。由于化学物质、代谢物和 degradates 的多样性和多样化, 非目标分析将成为它们在环境57中发现的最重要的分析武器。为有效消除, 污水处理厂的新阶段将需要根据先进的氧化工艺设计, 紫外线照射可能是其中的一部分。

药物在水生环境中经常被发现1,2,3,4,5。一个重要来源是污水处理厂的废水 (污水处理厂)6,7,8,9。图里亚流域10exemplarily 研究了整个水循环中的药物发生情况。在其他方面, 抗生素是一种特殊的危险类别的药物, 因为他们经常通过污水处理厂的生物阶段不变, 并可能导致细菌抵抗在环境11,12,13.抗生素是一种在人体和兽医中都适用的抗生素类药物。他们的代表在废水14,15,16,17,18,19被发现集中1µg/升。其中之一是红霉素 (20,21。在水中, 红霉素通常伴有 anhydroerythromycin a (一小时2O), 脱水22,23。红霉素的水消除是由于酸不稳定。红霉素与 anhydroerythromycin 的比值取决于 pH 值24、25、26、27。
化学上, 抗生素含有 macrocylic 内酯, 各种糖基团附着在一起, 例如, desosamine, cladinose 或 mycaminose。因为抗生素是化学修改的自然产品从发酵过程, 他们经常存在作为混合物。该物种称为 A、B、C 等, 不同于糖取代物。糖基团和他们的位置在内酯是负责任的行动方式抗生素28,29。为了尽量减少环境危害, 最好在进入水生环境27、30、31、32之前完全矿化药品。
本研究的第一部分是对地表水中药剂的检测, 这对于监测污水和开阔水域都是很重要的。为了在不同的矩阵中搜索微克范围内的各种不明物质, 非目标分析是选择20、33、34、35的方法。特别是高效液相色谱 (hplc) 电喷雾电离四极时间的飞行质谱 (hplc-ESI-Q-毫秒) 由于其特异性和敏感性而被证明具有非凡的价值。在物质的识别后, 灵敏度可以进一步扩展, 使用目标 MS 方法与四极运行在选择模式和碰撞能量在碰撞细胞设置为零。因此, 离子到达非碎片的飞行探测器。
这项工作的第二个重点是消除红霉素。为去除药物, 所谓的先进的氧化过程 (AOPs) 使用, e., 开始由辐照与紫外光36,37,38。降解的必要条件是在 eq 1 后, 通过紫外/紫外线照射从水中形成羟基自由基。
h2o + hν(< 200 nm) → h2o * → h . 哦 (1)
羟基自由基拥有高氧化电位 2.8 V, 正面地贡献对物质的退化36,37。
本文以 pH 值的影响为参考, 介绍了用真空紫外线/紫外辐照在水中降解红霉素的方法。更危险的产品的形成被认为是使用 AOPs39,40的缺点。因此, 重要的是要辐照, 直到完全成矿的药物。为了更好地估计辐照时间, 对初始药物及其 photodegradates 的反应动力学模型、反应速率常数和半衰期进行了测定。为此, 利用 MATLAB 对液相色谱-ESI-Q-毫秒-MS 测量进行了浓度-时间 (c-t) 图的提取, 并与化学动力学模型进行了比较。降解动力学按一阶进行, photodegradates 被描述为连续或后续反应27,41的中间产物。

<table><tbody><tr><td>Methanol for liquid chromatography LiChrosolv</td><td>Merck</td><td>1060181000</td><td></td></tr><tr><td>formic acid</td><td>Fluka</td><td>94318</td><td></td></tr><tr><td>HCl</td><td>Riedel-de Haen</td><td></td><td></td></tr><tr><td>NH3</td><td>Riedel-de Haen</td><td></td><td></td></tr><tr><td>Simplicity 185 Water Purification System</td><td>EMD Millipore</td><td></td><td>for producing MilliQ-water</td></tr><tr><td>Erythromycin</td><td>BioChemica AppliChem</td><td>A2275,0005</td><td></td></tr><tr><td>Filter Rotilabo-filter, Typ 113A</td><td>Roth</td><td>AP78.1</td><td></td></tr><tr><td>SPE-Cartridges Oasis HLB 3cc (60mg)</td><td>Waters</td><td>WAT094226</td><td></td></tr><tr><td>BAKER SPE-12G</td><td>J.T. Baker</td><td></td><td></td></tr><tr><td>membrane pump PC3001 VarioPro&amp;nbsp;</td><td>Vacuubrand</td><td></td><td></td></tr><tr><td>rotary evaporator; Laborota 4000 efficient</td><td>Heidolph Instruments</td><td></td><td></td></tr><tr><td>syringe, 2 mL</td><td>Terumo</td><td></td><td></td></tr><tr><td>Nylon Syringe Filters Target2</td><td>Thermo Scientific</td><td>10301345</td><td></td></tr><tr><td>C-18 CoreShell column 50 mm x 2.1 mm dimensions, 2.6 &amp;mu;m particle size</td><td>Thermo Scientific</td><td></td><td></td></tr><tr><td>HPLC 1200</td><td>Agilent</td><td></td><td></td></tr><tr><td>ESI-Q-ToF-MS 6530</td><td>Agilent</td><td></td><td></td></tr><tr><td>photoreactor, UV Labor Reactor System 3</td><td>Peschl Utraviolet GmbH</td><td></td><td></td></tr><tr><td>VUV/UVC-lamp, TNN 15/32, 15 W</td><td>Heraeus</td><td></td><td></td></tr><tr><td>pH-meter, pHenomenal pH 1100L</td><td>vwr</td><td>662-1657</td><td></td></tr><tr><td>magnetic stirrer</td><td>Heidolph Instruments</td><td></td><td></td></tr><tr><td>MassHunter Workstation B.06.00</td><td>Agilent</td><td></td><td></td></tr><tr><td>MATLAB R2016b</td><td>Mathworks</td><td></td><td></td></tr></tbody></table>

identification of pharmaceuticals in the aquatic environment using hplc-esi-q-tof-ms and elimination of erythromycin through photo-induced degradation

在整个水循环中监测药品对水生环境和最终对人类健康的重要性日益重要。目标和非目标分析是当今的选择手段。尽管通常在三重四极质谱仪的帮助下进行目标分析可能更敏感, 但只有先前选定的化合物才能被识别出来。最强大的非目标分析是通过使用四极质谱仪 (Q) 扩展的飞行质量光谱仪的时间进行的。在固相萃取和高效液相色谱 (HPLC) 的前面, 非靶向方法可以检测出高灵敏度和选择性的所有电离物质。通过对 Q-ms 仪器的充分利用, 串联质谱 (ms) 实验加速和促进了识别, 而靶向 ms 方法提高了灵敏度, 但依赖参考标准进行识别。证明了莱茵河河水中四种药物的鉴定。莱茵河发源于 Tomasee, 格劳宾登州, 瑞士并且流动入北海, 附近南海湾, 荷兰。它的长度共计1232.7 公里。由于从水循环中有效地消除药物是最重要的, 因此在实验室尺度上显示了紫外线辐射效应。这种方法可以快速降解药物, 这是 exemplarily 显示 macrolide 抗生素红霉素。采用上述 HPLC 法, 对母体药物及其光降解产物的浓度时间图进行了研究。在建立一阶序贯反应方程后, 计算拟合可以确定动力学参数, 这可能有助于预测辐照时间和条件时, 可能考虑第四阶段内废水处理。

由于固相萃取的结果, 在所有情况下都得到了黄到深绿色溶液, 这表明含有叶绿素的物质 (图 1)。这种水样中含有的药物不会导致可见的着色, 因为它们的浓度和吸收量一般都过低。相反, 需要用高效液相色谱和高分辨质谱分析药物的发生。
在非靶向分析中, 采用高效液相色谱-ESI-Q-MS, 由于其优异的质量准确度, 使每种化合物离子获得准确的质量。所做分析的质量检测色谱表示为基峰色谱 (BPC), 它显示了色谱分离过程中记录的每一质谱的最强峰值。图 2所示的例子显示了莱茵河的水样的原料药。
该原料药含有超过二十五个峰值, 反映不同的 m-/z 值, 因此不同的化合物, 其中七在原料药中标记。因为物质是未知的先验, 对他们的证明的第一步通常包括派生分子公式。这是通过飞行观测所提供的精确质量和同位素模式完成的, 尽管在所有情况下, 由于环境样品中样品浓度低, 同位素模式可能不会被观察到。在公共数据库的帮助下, 如德国环境署 (UBA) 所含的药物在环境中含有大约630种化合物, 初步确定一小部分候选者往往是成功的。对于最终的证明, 无论是与商业上可用的参考标准进行比较, 还是可以考虑 ms 或 ms 碎片模式 (图 3)。
在这项工作中, 相对于保留时间的标准而言, 在德国地表水中经常发现药物的鉴别。这些物质包括美托洛尔、β阻滞剂、卡马西平、镇痛药和 macrolide 抗生素红霉素 a 及其衍生物 anhydroerythromycin 红霉素作为进一步研究的例子。被研究的莱茵河河样品有 pH 值7.6 和平均温度16.5 °c。在这种 pH 值下, anhydroerythromycin 也有望出现在水样中。详细分析了水样中提取的离子图谱 (EICs) 与参考标准 (图 4) 的比较。
比较美托洛尔、卡马西平和 anhydroerythromycin 的保留时间与观察的分析结果吻合较好。参考标准 anhydroerythromycin 的 EIC 显示两个峰值, 因此两个化合物在红霉素的两个不同部位发生脱水。然而, 在莱茵河样品中只发现了一种 anhydroerythromycin 异构体。红霉素本身只存在于痕迹中。因此, 不能获得 ms 和 ms 谱。表 2给出了抗生素及其脱水的准确质量。使用 EIC, 因而 m/z 值和保留时间, 美托洛尔, carbamazepin, 红霉素和 anhydroerythromycin 可以在莱茵河河样品被辨认。
关于水生环境, 必须防止药品通过废水处理厂和进入地表水。为了寻求有效的消除, 以红霉素为例进行了不同 pH 值的紫外辐照实验。利用 EICs 的大面积和时间地块记录了浓度-时间 (c t) 图。退化被描述了根据等式2。红霉素由红霉素 a 和 B 和 anhydroerythromycin a 组成, 后者有两个异构体。红霉素 A 的c-t曲线及其计算拟合如图 5所示。pH 值为 7, 观察到加速降解。这适用于所研究的所有四种化合物, 没有显示数据。因此, 应在中性 pH 值的作用下, 对红霉素进行光诱导降解。在莱茵河样品的情况下, 不需要 pH 值调整。
Photodegradates 的药物也被确定在所有三 pH 值。表3给出了这些 photodegradates 及其相应结构建议的概览。对于 photodegradates 的动力学分析, 以 m/z 为720的产品为例。Photodegradates 通常可以被描述为反应中间体。因此, photodegradates 被描述为 aconsecutive 和随后的后续反应。所产生的中间体类型之间的决定是基于适当的软件计算的拟合的优点, 其中以确定系数 (R2) 和残差均方根误差 (RMSE) 作为准则。由于红霉素是酸不稳定的事实, degradates 就像会发生在辐照前存在。对方程3和4产生的影响是一个有限的起始浓度。因此, 公式中增加了一个因子。图 6显示了根据等式3和4计算的实验数据和符合性。
这个中间的例子证明了集中增量以 sigmoidal 上升跟随指数朽烂。这预示着随后的后续反应中间体。连续反应中间体不显示 sigmoidal 增加。统计质量参数还表明, 根据后续反应模型, 拟合符合性稍优。连续反应的 R2的测定系数为 0.9898, 因而低于后续反应的0.9976。因此, 被检查的 photoproduct 被解释作为后继的后续反应的中间。计算拟合结果的 k 值, 以及在等式5下计算半衰期。所有相关的动力学参数都在表 3中收集。
ph 值为7的最快降解, 其次是 ph 值 9, 而 ph 值为3时最慢的降解 (图 5)。这一发现也适用于 photoproducts 的形成和降解。观察到三 photodegradates。他们的 m-/z 值是750.46 对应于 F, 720.45 对 DPEry192 和192.12 对 glycosidically 的结合糖的红霉素结构 (图 7)。在 ph 值为3和9的 DPEry192, ph 值为9时, photoproduct 的降解不会被观察到。在这些情况下, 辐照时间不足以观察中间产物的总降解。然而, 形成率常数可以用等式5确定, 对应于最后的产品。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57434/57434fig1.jpg"> 图 1.从莱茵河 (左) 和超纯水 (右) 处理后的样品比较.绿色着色对含叶绿素物质有指示性。<a href="/files/ftp_upload/57434/57434fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/57434/57434fig2.jpg"> 图 2.用 HPLC-ESI-Q-质谱测定 SPE 后水样中的原料药.所有的图谱都归为最高峰。说明的 m/z 值, 从相应的 MS 频谱得到标记。<a href="/files/ftp_upload/57434/57434fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/57434/57434fig3.jpg"> 图 3.734.4689 (顶部) 红霉素 A (下) 和 ms/毫秒谱的 Q-毫秒谱。光谱显示了红霉素 A 的准分子离子, 其同位素模式和在 30 eV 应用碰撞能量中的片段。<a href="/files/ftp_upload/57434/57434fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/57434/57434fig4.jpg"> 图 4.规范化 EICs (A) 美托洛尔, (B) 卡马西平, (C) 红霉素 a 和 (D) anhydroerythromycin a 在莱茵河河样品 (蓝色) 和在超纯水从参考化合物 (红色).参考化合物的保留时间和在水样中的药物的保存次数相同。美托洛尔 (A) 和 anhydroerythromycin (D) 的信噪比高于卡马西平 (B) 和红霉素 (C), 表明后者仅存在于微量。<a href="/files/ftp_upload/57434/57434fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/57434/57434fig5.jpg"> 图 5.在 ph 值为 3 (红色)、ph 值 7 (绿色) 和 ph 9 (蓝色) 的红霉素的光降解的归一化浓度-时间曲线.溶液辐照10分钟。在 pH 值 7, 红霉素完全从样品中除去。利用一阶动力学方程可以描述浓度-时间曲线。动力学速率常数是 0.10 (ph 值 3), 0.59 (ph 7) 和 = 0.21 (ph 值 9)。<a href="/files/ftp_upload/57434/57434fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/57434/57434fig6.jpg"> 图 6.红霉素 photoprodegradates 浓度-时间曲线与 m/z = 720 在 pH 值9以下 3 (A) 和 4 (B) 之间的配合比较.连续反应的适当性 (A): r2 = 0.9898, RMSE = 4.645E + 04 和随后后续反应 (B): R2 = 09976, RMSE = 2.366E + 04。<a href="/files/ftp_upload/57434/57434fig6large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/57434/57434fig7.jpg"> 图 7.红霉素 A、红霉素 B、anhydroerythromycin 及其 photdegradation 产品的结构.这个数字已经从 Voigt. 27. 该产品是在10分钟紫外线照射后形成的, 采用 HPLC-Q-质谱-ms 和 ms (ms) 进行鉴别.<a href="/files/ftp_upload/57434/57434fig7large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<table fo:keep-together.within-page="1"><tbody>
<tr>
<td>液相色谱</td>
			<td colspan="6"></td>
		</tr>
<tr>
<td>列:</td>
			<td colspan="6">反相 C-18</td>
		</tr>
<tr>
<td>列:</td>
			<td colspan="6">CoreShell 柱;</td>
		</tr>
<tr>
<td>列:</td>
			<td colspan="6">50毫米 x 2.1 毫米尺寸, 2.6 微米粒度</td>
		</tr>
<tr>
<td>柱温</td>
			<td colspan="6">40°c</td>
		</tr>
<tr>
<td>注塑量:</td>
			<td colspan="6">5µL</td>
		</tr>
<tr>
<td>流:</td>
			<td colspan="6">0.3 毫升/分</td>
		</tr>
<tr>
<td>移动阶段:</td>
			<td colspan="6">溶剂 A: 含0.1% 甲酸的水</td>
		</tr>
<tr>
<td></td>
			<td colspan="6">溶剂 B: 含有0.1% 甲酸的甲醇</td>
		</tr>
<tr>
<td>渐变程序:</td>
			<td colspan="6"></td>
		</tr>
<tr>
<td>时间/分钟</td>
			<td>0</td>
			<td>1</td>
			<td>10</td>
			<td>11。1</td>
			<td>11。2</td>
			<td>12</td>
		</tr>
<tr>
<td>a: B 溶剂比</td>
			<td>99:1</td>
			<td>70:30</td>
			<td>25:75</td>
			<td>1:99</td>
			<td>1:99</td>
			<td>99:1</td>
		</tr>
<tr>
<td>质谱</td>
			<td colspan="6"></td>
		</tr>
<tr>
<td>源:</td>
			<td colspan="6">双 AJS ESI (正模式)</td>
		</tr>
<tr>
<td>气体和源</td>
			<td colspan="6"></td>
		</tr>
<tr>
<td>气体温度:</td>
			<td colspan="6">300°c</td>
		</tr>
<tr>
<td>干燥气体:</td>
			<td colspan="6">8.0 升/分</td>
		</tr>
<tr>
<td>雾化器:</td>
			<td colspan="6">14 psig</td>
		</tr>
<tr>
<td>护套气体温度:</td>
			<td colspan="6">300°c</td>
		</tr>
<tr>
<td>鞘气流量:</td>
			<td colspan="6">8升/分</td>
		</tr>
<tr>
<td>质量范围:</td>
			<td colspan="6">100-1000 米/z</td>
		</tr>
<tr>
<td>收购率:</td>
			<td colspan="6">1频谱/秒</td>
		</tr>
<tr>
<td>购置时间:</td>
			<td colspan="6">1000毫秒/频谱</td>
		</tr>
<tr>
<td>瞬态/频谱</td>
			<td colspan="6">10014</td>
		</tr>
<tr>
<td>针对目标 MS 方法</td>
			<td colspan="6"></td>
		</tr>
<tr>
<td>碰撞能 (CE):</td>
			<td colspan="6">0 eV</td>
		</tr>
<tr>
<td>首选质量表</td>
			<td colspan="6">734.4685</td>
		</tr>
<tr>
<td>对于 ms/毫秒 (通常是自动 ms 或 ms 模式)</td>
			<td colspan="6"></td>
		</tr>
<tr>
<td>碰撞能 (CE):</td>
			<td colspan="6">30 eV</td>
		</tr>
<tr>
<td>绝对阈值</td>
			<td colspan="6">3000计数</td>
		</tr>
<tr>
<td>相对阈值</td>
			<td colspan="6">0.01%</td>
		</tr>
<tr>
<td>质量范围:</td>
			<td colspan="6">100-100 米/z</td>
		</tr>
<tr>
<td>收购率:</td>
			<td colspan="6">1频谱/秒</td>
		</tr>
<tr>
<td>购置时间:</td>
			<td colspan="6">1000毫秒/频谱</td>
		</tr>
<tr>
<td>瞬态/频谱</td>
			<td colspan="6">9964</td>
		</tr>
<tr>
<td>针对目标 ms/ms 方法</td>
			<td colspan="6"></td>
		</tr>
<tr>
<td>首选质量表</td>
			<td colspan="6">734.4685</td>
		</tr>
</tbody></table>表1。水基质中药物的 HPLC-ESI-Q-质谱分析的条件和参数.建议通过在两种分析之间或通过延长色谱法的运行时间来洗脱所有物质, 在色谱的运行之间引入一个漂洗步骤。
<img alt="Table 2" src="/files/ftp_upload/57434/57434table2.jpg"> 表2。在莱茵河样品发现的药剂以他们的保留时间、理论和观察 [M + H]+ 和他们的结构.ESI 模式设置为正, 以便检测到 [M + H]+离子。由于通常的实验已知的原因, 保留时间可能会有极小的变化。
<table fo:keep-together.within-page="1"><tbody>
<tr>
<td></td>
			<td>pH 值3</td>
			<td>pH 值3</td>
			<td>pH 值7</td>
			<td>pH 值7</td>
			<td>pH 值7</td>
			<td>pH 值7</td>
			<td>pH 值7</td>
			<td>pH 值7</td>
			<td>pH 值9</td>
			<td>pH 值9</td>
			<td>pH 值9</td>
			<td>pH 值9</td>
		</tr>
<tr>
<td>产品</td>
			<td>k1 [最少-1]</td>
			<td>t1/2 [分钟] (k1)</td>
			<td>k1 [最少-1]</td>
			<td>k2 [最少-1]</td>
			<td>k3 [最少-1]</td>
			<td>t1/2 [分钟] (k1)</td>
			<td>t1/2 [分钟] (k2)</td>
			<td>t1/2 [分钟] (k3)</td>
			<td>k1 [最少-1]</td>
			<td>k2 [最少-1]</td>
			<td>t1/2 [分钟] (k1)</td>
			<td>t1/2 [分钟] (k2)</td>
		</tr>
<tr>
<td>一</td>
			<td>0。1</td>
			<td>6.81</td>
			<td>0.59</td>
			<td>-</td>
			<td>-</td>
			<td>1.18</td>
			<td>-</td>
			<td>-</td>
			<td>0.21</td>
			<td>-</td>
			<td>3.37</td>
			<td>-</td>
		</tr>
<tr>
<td>B</td>
			<td>0.05</td>
			<td>14.23</td>
			<td>0.66</td>
			<td>-</td>
			<td>-</td>
			<td>1.04</td>
			<td>-</td>
			<td>-</td>
			<td>0.22</td>
			<td>-</td>
			<td>3.21</td>
			<td>-</td>
		</tr>
<tr>
<td>A-H2Oa</td>
			<td>0.11</td>
			<td>6.53</td>
			<td>0.59</td>
			<td>-</td>
			<td>-</td>
			<td>1.17</td>
			<td>-</td>
			<td>-</td>
			<td>0.19</td>
			<td>-</td>
			<td>3.72</td>
			<td>-</td>
		</tr>
<tr>
<td>A-H2转播</td>
			<td>0.15</td>
			<td>4.76</td>
			<td>1.11</td>
			<td>-</td>
			<td>-</td>
			<td>0.63</td>
			<td>-</td>
			<td>-</td>
			<td>0.21</td>
			<td>-</td>
			<td>3.35</td>
			<td>-</td>
		</tr>
<tr>
<td>F</td>
			<td>未观察到</td>
			<td>-</td>
			<td>0.89</td>
			<td>0.35</td>
			<td>-</td>
			<td>0.78</td>
			<td>1.98</td>
			<td>-</td>
			<td>1.09 *</td>
			<td>-</td>
			<td>0.64</td>
			<td>-</td>
		</tr>
<tr>
<td>C</td>
			<td>未确定</td>
			<td>-</td>
			<td>0.74</td>
			<td>5.27</td>
			<td>0.78</td>
			<td>0.94</td>
			<td>0.13</td>
			<td>0.89</td>
			<td>0.17</td>
			<td>0.18</td>
			<td>4.04</td>
			<td>3.92</td>
		</tr>
<tr>
<td>DPEry192</td>
			<td>0.35 *</td>
			<td>1.97</td>
			<td>未观察到</td>
			<td>-</td>
			<td>-</td>
			<td>-</td>
			<td>-</td>
			<td>-</td>
			<td>0.30 *</td>
			<td>-</td>
			<td>2.34</td>
			<td>-</td>
		</tr>
<tr>
<td colspan="13">* 无进一步退化观察</td>
		</tr>
</tbody></table>表3。photodegradates 的动力学速率常数和相应的半衰期, 并从 Voigt 等方面对红霉素的降解进行了研究。27. 红霉素由红霉素 A、红霉素 B 和两种形式的 anhydroerythromycin 组成。观察到三 photodegradates。这里被称为 F、C 和 DEry192。

Watch this Scientific Journal Video about Identification of Pharmaceuticals in The Aquatic Environment Using HPLC-ESI-Q-TOF-MS and Elimination of Erythromycin Through Photo-Induced Degradation at JoVE

Identification of Pharmaceuticals in The Aquatic Environment Using HPLC-ESI-Q-TOF-MS and Elimination of Erythromycin Through Photo-Induced Degradation

我们提出了一个非目标分析的协议, 利用时间的飞行质谱作为一个完美的工具, 以识别水中的药物。我们演示了紫外线照射的应用, 以消除它们。对降解剖面的辐照、复合隔离、识别和动力学建模进行了分析。

高效液相色谱-ESI-Q-MS 与红霉素通过光致降解法鉴定水生环境中的药物

Monitoring pharmaceuticals throughout the water cycle is becoming increasingly important for the aquatic environment and eventually for human health. ...

identification-pharmaceuticals-aquatic-environment-using-hplc-esi-q

Nanyang Technological University

Research

JoVE Journal

Environment

13.0K 次观看.  Niederrhein University of Applied Sciences. 我们提出了一个非目标分析的协议, 利用时间的飞行质谱作为一个完美的工具, 以识别水中的药物。我们演示了紫外线照射的应用, 以消除它们。对降解剖面的辐照、复合隔离、识别和动力学建模进行了分析。

视频: Identification of Pharmaceuticals in The Aquatic Environment Using HPLC-ESI-Q-TOF-MS and Elimination of Erythromycin Through Photo-Induced Degradation

Improved Polymerase Chain Reaction-restriction Fragment Length Polymorphism Genotyping of Toxic Pufferfish by Liquid Chromatography/Mass Spectrometry

An improved version of a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method for genotyping toxic pufferfish species by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) is described. DNA extraction is carried out using a silica membrane-based DNA extraction kit. After the PCR amplification using a detergent-free PCR buffer, restriction enzymes are added to the solution without purifying the reaction solution. A reverse-phase silica monolith column and a Fourier transform high resolution mass spectrometer having a modified Kingdon trap analyzer are employed for separation and detection, respectively. The mobile phase, consisting of 400 mM 1,1,1,3,3,3-hexafluoro-2-propanol, 15 mM triethylamine (pH 7.9) and methanol, is delivered at a flow rate of 0.4 ml/min. The cycle time for LC/ESI-MS analysis is 8 min including equilibration of the column. Deconvolution software having an isotope distribution model of the oligonucleotide is used to calculate the corresponding monoisotopic mass from the mass spectrum. For analysis of oligonucleotides (range 26-79 nucleotides), mass accuracy was 0.62 &#177; 0.74 ppm (n = 280) and excellent accuracy and precision were sustained for 180 hr without use of a lock mass standard.

An improved polymerase chain reaction-restriction fragment length polymorphism method for genotyping pufferfish species by liquid chromatography/mass spectrometry is described. A reverse-phase silica monolith column is employed for separating digested amplicons. This method can elucidate the monoisotopic masses of oligonucleotides, which is useful for identifying base composition.

河豚有毒改进的聚合酶链反应 - 限制性片段长度多态性分型液相色谱/质谱法

An improved version of a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method for genotyping toxic pufferfish species by ...

科研

遗传学

A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17&#946;-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 &#181;l of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.

A protocol for the extraction and pre-concentration of estradiol from water samples by using an automated and miniaturized system is presented.

对水样的自动固相萃取小污染物的免疫学分析的简单方法

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and ...

环境科学

Use of a Battery of Chemical and Ecotoxicological Methods for the Assessment of the Efficacy of Wastewater Treatment Processes to Remove Estrogenic Potency

Endocrine Disrupting Compounds pose a substantial risk to the aquatic environment. Ethinylestradiol (EE2) and estrone (E1) have recently been included in a watch list of environmental pollutants under the European Water Framework Directive. Municipal wastewater treatment plants are major contributors to the estrogenic potency of surface waters. Much of the estrogenic potency of wastewater treatment plant (WWTP) effluents can be attributed to the discharge of steroid estrogens including estradiol (E2), EE2 and E1 due to incomplete removal of these substances at the treatment plant. An evaluation of the efficacy of wastewater treatment processes requires the quantitative determination of individual substances most often undertaken using chemical analysis methods. Most frequently used methods include Gas Chromatography-Mass Spectrometry (GCMS/MS) or Liquid Chromatography-Mass Spectrometry (LCMS/MS) using multiple reaction monitoring (MRM). Although very useful for regulatory purposes, targeted chemical analysis can only provide data on the compounds (and specific metabolites) monitored. Ecotoxicology methods additionally ensure that any by-products produced or unknown estrogenic compounds present are also assessed via measurement of their biological activity. A number of in vitro bioassays including the Yeast Estrogen Screen (YES) are available to measure the estrogenic activity of wastewater samples. Chemical analysis in conjunction with in vivo and in vitro bioassays provides a useful toolbox for assessment of the efficacy and suitability of wastewater treatment processes with respect to estrogenic endocrine disrupting compounds. This paper utilizes a battery of chemical and ecotoxicology tests to assess conventional, advanced and emerging wastewater treatment processes in laboratory and field studies.

Endocrine Disrupting Compounds (EDC) pose a substantial risk to the aquatic environment. Municipal wastewater treatment plants are major contributors to the estrogenic potency of surface waters. The methodology provided in this paper allows for an assessment of the efficacy and suitability of wastewater treatment processes with respect to EDC removal.

对污水处理工艺的疗效评估利用化学和生态毒理学方法的电池，以消除雌激素潜能

Endocrine Disrupting Compounds pose a substantial risk to the aquatic environment. Ethinylestradiol (EE2) and estrone (E1) have recently been included in ...

Identifying Per- and Polyfluorinated Chemical Species with a Combined Targeted and Non-Targeted-Screening High-Resolution Mass Spectrometry Workflow

Historical and emerging per- and polyfluoroalkyl substances (PFASs) have garnered significant interest from the public and government agencies from the local to federal levels. The continuing evolution of PFAS chemistries presents a challenge to the environmental monitoring, where ongoing development of targeted methods necessarily lags the discovery of new chemical compounds. There is a need, therefore, to have forward-looking methodologies that can detect emerging and unexpected compounds, monitor these species over time, and resolve details of their chemical structure to enable future work in human health. To this end, non-targeted analysis by high-resolution mass spectrometry offers a broad base detection approach that can be combined with almost any sample preparation scheme and provides significant capabilities for compound identification after detection. Herein, we describe a solid-phase extraction (SPE) based sample concentration method tuned for shorter chain and more hydrophilic PFAS chemistries, such as per fluorinated ether acids and sulfonates, and describe analysis of samples prepared in this fashion in both targeted and non-targeted modes. Targeted methods provide superior quantification when reference standards are available but are intrinsically limited to expected compounds when performing analysis. In contrast, a non-targeted approach can identify the presence of unexpected compounds and provide some information about their chemical structure. Information about chemical features can be used to correlate compounds across sample locations and track abundance and occurrence over time.

Here, we present a protocol for the sequential targeted quantification and non-targeted analysis of fluorinated compounds in water by mass spectrometry. This methodology provides quantitative levels of known fluorochemical compounds and identifies unknown chemicals in related samples with semi-quantitative estimates of their abundance.

利用目标筛选和非靶向筛选高分辨率质谱相结合的工作流程识别跨氟和多氟化学物种

Historical and emerging per- and polyfluoroalkyl substances (PFASs) have garnered significant interest from the public and government agencies from the ...

A Complete Method for Evaluating the Performance of Photocatalysts for the Degradation of Antibiotics in Environmental Remediation

Various antibiotics such as tetracycline, aureomycin, amoxicillin, and levofloxacin are found in large quantities in groundwater and soil systems, potentially leading to the development of resistant and multi-drug resistant bacteria, posing a threat to humans, animals, and environmental systems. Photocatalytic technology has attracted keen interest due to its rapid and stable treatment and direct use of solar energy. However, most studies evaluating the performance of semiconductor catalysts for the photocatalytic degradation of organic pollutants in water are currently incomplete. In this paper, a complete experimental protocol is designed to comprehensively evaluate the photocatalytic performance of semiconductor catalysts. Herein, rhombic dodecahedral silver phosphate was prepared by a simple solvent phase synthesis method at room temperature and atmospheric pressure. BrSubphthalocyanine/Ag3PO4 heterojunction materials were prepared by the solvothermal method. The catalytic performance of as-prepared materials for the degradation of tetracycline was evaluated by studying different influencing factors such as catalyst dosage, temperature, pH, and anions at atmospheric pressure using a 300 W xenon lamp as a simulated solar light source and a light intensity of 350 mW/cm2. Compared with the first cycle, the constructed BrSubphthalocyanine/Ag3PO4 maintained 82.0% of the original photocatalytic activity after five photocatalytic cycles, while the pristine Ag3PO4 maintained only 28.6%. The stability of silver phosphate samples was further tested by a five-cycle experiment. This paper provides a complete process for evaluating the catalytic performance of semiconductor catalysts in the laboratory for the development of semiconductor catalysts with potential for practical applications.

Presented here is a protocol to explore a universal set of experimental procedures for comprehensive laboratory evaluation of photocatalysts in the field of environmental purification, using the example of photocatalytic removal of antibiotic organic pollutant molecules from water by phthalocyanine sensitized silver phosphate composites.

一种评价光催化剂降解环境修复中抗生素性能的完整方法

Various antibiotics such as tetracycline, aureomycin, amoxicillin, and levofloxacin are found in large quantities in groundwater and soil systems, ...

High-throughput and Comprehensive Drug Surveillance Using Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry

New analytical methods are urgently needed to enable high-throughput, yet comprehensive drug screening, given an alarming opioid and prescription drug crisis in public health. Conventional urine drug testing based on a two-tier immunoassay screen followed by a gas chromatography-tandem mass spectrometry (GC-MS/MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) method are expensive and prone to bias while being limited to targeted panels of known drugs of abuse (DoA). Herein, we outline an improved method for drug surveillance that allows for the resolution and detection of an expanded panel of DoA and their metabolites when using multisegment injection-capillary electrophoresis-mass spectrometry (MSI-CE-MS). Multiplexed separations of ten urine samples with a quality control by CE (&lt; 3 min/sample) in conjunction with full-scan data acquisition using a time-of-flight mass spectrometer (TOF-MS) under positive ion mode detection allows for the identification and quantification of DoA above recommended cut-off levels. An excellent resolution of drug isomers and isobars, including background interferences, are achieved when using MSI-CE-MS with an electrokinetic spacer between sample segments, where accurate mass/molecular formula together with the comigration of a matching deuterated internal standard and the detection of one or more bio-transformed metabolites facilitate DoA identification over a wider detection window. Additionally, urine samples can be analyzed directly without enzyme deconjugation for the rapid screening without complicated sample workup. MSI-CE-MS enables the surveillance of a broad spectrum of DoA that is required for the treatment monitoring of high-risk patients, including confirming prescribed drug adherence, revealing illicit drug use/substitution, and evaluating optimal dosage regimes as required for new advances in precision medicine.

Here we describe a high-throughput method for comprehensive drug surveillance that allows for the improved resolution and detection of large panels of drugs of abuse and their metabolites, with quality control based on multisegment injection-capillary electrophoresis-mass spectrometry.

采用多段注射-毛细管电泳质谱法进行高通量和综合药物监测

New analytical methods are urgently needed to enable high-throughput, yet comprehensive drug screening, given an alarming opioid and prescription drug ...

化学

Early Detection of Cyanobacterial Blooms and Associated Cyanotoxins using Fast Detection Strategy

Fast detection of cyanobacteria and cyanotoxins is achieved using a Fast Detection Strategy (FDS). Only 24 h are needed to unravel the presence of cyanobacteria and related cyanotoxins in water samples and in an organic matrix, such as bivalve extracts. FDS combines remote/proximal sensing techniques with analytical/bioinformatics analyses. Sampling spots are chosen through multi-disciplinary, multi-scale, and multi-parametric monitoring in a three-dimensional physical space, including remote sensing. Microscopic observation and taxonomic analysis of the samples are performed in the laboratory setting, which allows for the identification of cyanobacterial species. Samples are then extracted with organic solvents and processed with LC-MS/MS. Data obtained by MS/MS are analyzed using a bioinformatic approach using the online platform Global Natural Products Social (GNPS) to create a network of molecules. These networks are analyzed to detect and identify toxins, comparing data of the fragmentation spectra obtained by mass spectrometry with the GNPS library. This allows for the detection of known toxins and unknown analogues that appear related in the same molecular network.

A fast-multidisciplinarystrategy for early detection of cyanobacterial blooms and associated cyanotoxins is described here. It allows for the detection of cyanobacteria and related cyanotoxins in water samples and in organic matrices, such as bivalve samples, in 24 h.

使用快速检测策略早期检测蓝藻花和相关氰毒素

Fast detection of cyanobacteria and cyanotoxins is achieved using a Fast Detection Strategy (FDS). Only 24 h are needed to unravel the presence of ...

<meta charset="utf8"></head><body>使用 LC-IMS-MS 增强麦角生物碱的异构体分离

Detection of Regulated Ergot Alkaloids in Food Matrices by Liquid Chromatography-Trapped Ion Mobility Spectrometry-Time-of-Flight Mass Spectrometry

Ion mobility mass spectrometry (IMS) acts as an additional separation dimension when integrated into liquid chromatography-mass spectrometry (LC-MS) workflows. LC-IMS-MS methods provide higher peak resolution, enhanced separation of isobaric and isomeric compounds, and improved signal-to-noise ratio (S/N) compared to traditional LC-MS methods. IMS provides another molecular characteristic for the identification of analytes, namely the collision cross section (CCS) parameter, reducing false positive results. Therefore, LC-IMS-MS methods address important analytical challenges in the field of food safety (i.e., detection of compounds at trace levels in complex food matrices and unambiguous identification of isobaric and isomeric molecules).
Ergot alkaloids (EAs) are a family of mycotoxins produced by fungi that attack a wide variety of grass species, including small grains such as rye, triticale, wheat, barley, millet, and oats. Maximum levels (MLs) of these mycotoxins have been established in several foodstuffs, as detailed in the Commission Regulation EC/2023/915. This new legislation includes six main EAs and their corresponding epimers, so an efficient methodology is required to properly distinguish these isomeric molecules considering their co-occurrence.
Therefore, the goal of this protocol is to show how the integration of IMS in LC-MS workflows contributes to the separation of isomeric EAs, enhancing the selectivity of the analytical method. Additionally, it illustrates how the generation of CCS libraries through the characterization of analytical standards provides higher confidence for the identification of mycotoxins. This protocol is designed to clearly explain the benefits of implementing IMS in food safety, taking as an example the determination of EAs in cereals. A QuEChERS-based extraction followed by an LC-trapped ion mobility spectrometry (TIMS)-MS analysis provided limits of quantification ranging from 0.65 to 2.6 ng/g with acceptable accuracy (although low recovery for ergotaminine) at 1.5x, 1x, and 0.5x the ML and exhibited a negligible matrix effect.

<meta charset="utf8"></head><body>通过液相色谱-捕获离子迁移谱-飞行时间质谱法检测食品基质中受管制的麦角生物碱

This protocol presents a validated liquid chromatography-ion mobility-high resolution mass spectrometry method to determine the presence of ergot alkaloids in food in compliance with the recently released Commission Regulation (EU) 2023/915.

通过液相色谱-捕获离子迁移谱-飞行时间质谱法检测食品基质中受管制的麦角生物碱

Ion mobility mass spectrometry (IMS) acts as an additional separation dimension when integrated into liquid chromatography-mass spectrometry (LC-MS) ...

高效液相色谱-ESI-Q-MS 与红霉素通过光致降解法鉴定水生环境中的药物

摘要

探索更多视频

此视频中的章节

河豚有毒改进的聚合酶链反应 - 限制性片段长度多态性分型液相色谱/质谱法

对水样的自动固相萃取小污染物的免疫学分析的简单方法

对污水处理工艺的疗效评估利用化学和生态毒理学方法的电池，以消除雌激素潜能

利用目标筛选和非靶向筛选高分辨率质谱相结合的工作流程识别跨氟和多氟化学物种

一种评价光催化剂降解环境修复中抗生素性能的完整方法

采用多段注射-毛细管电泳质谱法进行高通量和综合药物监测

使用快速检测策略早期检测蓝藻花和相关氰毒素

通过液相色谱-捕获离子迁移谱-飞行时间质谱法检测食品基质中受管制的麦角生物碱

通过液相色谱-捕获离子迁移谱-飞行时间质谱法检测食品基质中受管制的麦角生物碱

通过液相色谱-捕获离子迁移谱-飞行时间质谱法检测食品基质中受管制的麦角生物碱