作者希望承认托莱多大学开办的资金, 以及美国化学学会赫尔曼 Frasch 基金会的资金, 部分支持这项工作。托马斯爱上先生得到了他的帮助, 他开发了一个合适的压力表来测量反应压力。史蒂夫. Modar 先生对有用的讨论表示感谢。

警告: 1) 通过反复试验, 下列议定书被认为是安全的。然而, 当密封瓶, 在整个反应, 特别是当打开反应时应谨慎, 因为反应瓶的不均匀性可能导致设备故障。在使用前, 应检查瓶子的物理缺陷。瓶子应该被放置在某种形式的爆炸盾或罩窗扇后, 立即密封, 以防止事故, 如果瓶子失败。2) 虽然几乎没有机会窒息由于少量 CO2使用, 反应应该被设置并且打开在一个通风良好的区域或在通风罩。3) 干冰是一种制冷剂, 会引起严重的组织损伤。因此, 在操作时应谨慎, 以避免冻伤, 例如限制直接接触或使用低温手套。4) 干冰将凝结水蒸气, 即在使用前, 干冰应机械脱落, 以确保质量仅为 CO2 (s) 。这可以通过简单地摩擦手指之间的干冰, 或者更安全地, 在手指之间用一个防护层 (如手套或毛巾) 摩擦它来实现。
1. 7.5 毫升瓶中的反应 (空气不被排除)
<ol><li>在干燥的7.5 毫升瓶中加入搅拌条。</li>
	<li>将醋酸钯 (6.7 毫克, 0.03 毫摩尔) 加入瓶中。</li>
	<li>将三氟乙酸银 (99.9 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将苯基碘化物 (92.3 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将叔戊胺 (26.3 毫克, 0.30 毫摩尔) 加入瓶中。</li>
	<li>将醋酸 (1.0 毫升) 添加到瓶子里。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>加入去离子水 (21.7 ul, 12.1 毫摩尔) 的瓶子。</li>
	<li>称干冰 (26.3 毫克, 0.60 毫摩尔), 并立即加入干冰的瓶子, 同时确保也立即密封瓶聚四氟乙烯衬里帽。 注: 整个操作应在大约5秒内进行, 以防止在少量 CO2添加的升华和逃逸 (这是缓慢的形成冷冻醋酸周围的干冰)。增加 CO2的数量将是一个近似价值, 并且在我们的手少量镁的偏差是可允许的。</li>
	<li>在室温下将密封反应瓶搅拌15分钟。</li>
	<li>将反应容器转移到预热板110摄氏度, 搅拌14小时, 然后才允许冷却。</li>
	<li>冷却后, 小心打开小瓶, 以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在小瓶中执行, 也可以将溶液转移到较大的圆底烧瓶中。</li>
	<li>加入1.2 米 HCl (蒽醌) (6 毫升) 的反应混合物和搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (4 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 10 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基4苯基丁胺) 作为黄油。</li>
</ol>2. 7.5 毫升瓶中的反应 (净化条件–排除空气)
<ol><li>在干燥的7.5 毫升瓶中加入搅拌条。</li>
	<li>将醋酸钯 (6.7 毫克, 0.03 毫摩尔) 加入瓶中。</li>
	<li>将三氟乙酸银 (99.9 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将苯基碘化物 (92.3 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将叔戊胺 (26.3 毫克, 0.30 毫摩尔) 加入瓶中。</li>
	<li>将醋酸 (1.0 毫升) 添加到瓶子里。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>加入去离子水 (21.7 ul, 12.1 毫摩尔) 的瓶子。</li>
	<li>把瓶子的平衡, 添加约98毫克干冰, 然后允许 CO2升华, 直到最终质量约26毫克达到, 然后立即密封瓶与聚四氟乙烯衬里帽。 注: 如果可取, 这一步骤可以执行与更多的干冰, 进一步排除空气从瓶子。值得注意的是, 这可能会引入水, 因此可能不是最有效的水敏感反应策略。</li>
	<li>在室温下将密封反应瓶搅拌15分钟。</li>
	<li>将反应容器转移到预热板110摄氏度, 搅拌14小时, 然后才允许冷却。</li>
	<li>冷却后, 小心打开小瓶, 以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在小瓶中执行, 也可以将溶液转移到较大的圆底烧瓶中。</li>
	<li>加入1.2 米 HCl (蒽醌) (6 毫升) 的反应混合物, 并搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (4 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 10 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基4苯基丁胺) 作为黄油。</li>
</ol>3. 40 毫升瓶中的反应 (空气不被排除)
<ol><li>在干燥的40毫升瓶中加入搅拌条。</li>
	<li>将醋酸钯 (33.5 毫克, 0.15 毫摩尔) 加入瓶中。</li>
	<li>将三氟乙酸银 (499.5 毫克, 2.25 毫摩尔) 加入瓶子。</li>
	<li>将苯基碘化物 (461.5 毫克, 2.25 毫摩尔) 加入瓶子。</li>
	<li>将叔戊胺 (131.5 毫克, 1.5 毫摩尔) 加入瓶中。</li>
	<li>将醋酸 (5.0 毫升) 添加到瓶子里。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>加入去离子水 (108.5 ul, 6.02 毫摩尔) 的瓶子。</li>
	<li>称干冰 (131.5 毫克, 3.0 毫摩尔), 并立即加入干冰的瓶子, 同时确保也立即密封瓶聚四氟乙烯衬里帽。 注: 整个操作应在大约5秒内进行, 以防止在少量 CO2添加的升华和逃逸 (这是缓慢的形成冷冻醋酸周围的干冰)。增加 CO2的数量将是一个近似价值, 并且在我们的手少量镁的偏差是可允许的。</li>
	<li>在室温下将密封反应瓶搅拌15分钟。</li>
	<li>将反应容器转移到预热板110摄氏度, 搅拌14小时, 然后才允许冷却。</li>
	<li>冷却后, 小心打开小瓶, 以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在小瓶中执行, 也可以将溶液转移到较大的圆底烧瓶中。</li>
	<li>加入1.2 米 HCl (蒽醌) (30 毫升) 的反应混合物和搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (20 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 20 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基4苯基丁胺) 作为黄油。</li>
</ol>4. 35 毫升压力管中的反应 (空气不排除)
<ol><li>在干35毫升压力管中加入搅拌条。</li>
	<li>将醋酸钯 (6.7 毫克, 0.03 毫摩尔) 添加到压力管上。</li>
	<li>将三氟乙酸银 (132.5 毫克, 0.6 毫摩尔) 添加到压力管上。</li>
	<li>将苯基碘化物 (183.6 毫克, 0.9 毫摩尔) 添加到压力管上。</li>
	<li>添加 2-甲基n-(3-甲基苄基) 氨基正丁2胺 (57.4 毫克, 0.3 毫摩尔) 到压力管。</li>
	<li>将醋酸 (1.0 毫升) 添加到瓶子, 后跟 11, 13, 33,-hexafluoroisopropanol (1.0 毫升)。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>添加去离子水 (21.7 ul, 1.2 毫摩尔) 到压力管。</li>
	<li>称干冰 (1.32 克, 30 毫摩尔), 并立即加入干冰到压力管, 同时确保也立即密封的压力管与适当的聚四氟乙烯螺钉帽。 注: 整个操作应在大约5秒内进行, 以防止在少量 CO2添加的升华和逃逸 (这是缓慢的形成冷冻醋酸周围的干冰)。增加 CO2的数量将是一个近似价值, 并且在我们的手少量镁的偏差是可允许的。</li>
	<li>在室温下将密封反应釜搅拌15分钟。</li>
	<li>将反应容器转移到预热板90摄氏度, 搅拌24小时, 然后才允许冷却。</li>
	<li>冷却后, 在瓶盖上放一条毛巾或软垫手套, 并小心地打开压力管以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在压力管中使用适当的适配器, 或者解决方案可以转移到更大的圆底烧瓶。</li>
	<li>加入1.2 米 HCl (蒽醌) (12 毫升) 的反应混合物和搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (8 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可以处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 10 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基-n-(3-苄基)-4-丁醇2胺) 作为黄油。</li>
</ol>

使用 CO2作为一个指挥小组为 C H 活化刘易斯基本的基体是当前美国临时专利 #62 的焦点608074。

利用范德华状态方程, 可以计算出这些系统的近似压强45 。
情商 1:<img alt="Equation" src="/files/ftp_upload/58281/58281eq1.jpg">
在协议1的条件下, 我们可以假设26.3 毫克的 CO2给n = 5.98 x 10-4 mols
<img alt="Equation 1b" src="/files/ftp_upload/58281/58281eq2.jpg">
粗略估计, 这表明在1号议定书中, 反?...

气体化合物在化学反应中的使用通常需要专门的设备和程序1,2。在工作台刻度上, 某些气体可以直接从油箱中添加, 使用高压调节器3。另一种方法是在低温条件下冷凝气体4,5。虽然有用, 这些战略需要使用专门的压力反应堆与阀门, 这可能是成本高昂的运行许多反应并行。因此, 这可以大大减慢反应筛查的速度。因此, 化学家们发现使用其他方法来介绍这些化合物是可取的。氨可以添加到反应使用不同的羧酸铵盐, 利用弱平衡, 这些盐和自由氨6。转移氢化是烯烃、羰基和硝基基团还原反应的重要策略, 它绕过了以甲酸铵或肼等化合物为 H27的载体的易燃氢气的使用。另一种对这一地区感兴趣的气体是一氧化碳8 -co 可以通过从金属羰基络合物9,10的解放原位产生, 也可以由脱羰产生。来源如合成和芳基11,12,13或氯仿14,15。
在这方面没有取得重大进展的一种气体是二氧化碳16。其中一个原因是, 涉及 CO2的许多转换也需要高温和压力, 因此自动降级到专门的反应堆17,18。然而, 最近开发更多反应性催化剂的努力促进了在 CO219、20、21、22的大气压下运行许多这些反应。我们最近发现了一种反应, 其中二氧化碳可以用来调解γ C (sp3) –H arylation 脂肪胺23。这一战略预计将结合静态指导组方法的好处, 包括酰胺24,25,26,27,28, 磺胺类药物29,30,31,32, thiocarbonyl33,34, 或腙35基指挥小组 (化学鲁棒性), 以容易瞬变指挥小组(减少的步经济)36, 37,38,39。
尽管反应可能发生在 CO2的大气压下, 但对筛查反应的 Schlenk 的需要却是缓慢的。此外, 增加的压力轻微导致改善反应的收益率, 但不能轻易实现使用 Schlenk 线。因此, 我们寻求一种替代战略, 随后确定干冰可以很容易地用作 CO2的固体来源, 可以添加到各种反应容器中, 引入必要量的二氧化碳, 以达到适度压力 (图 1)。虽然在合成中未充分利用, 类似的策略是相当常见的一种方法来生成液体 CO2用于色谱和萃取应用40,41,42,43, 44。利用这一策略, 我们的小组能够快速地筛查大量的反应, 而在2-20 大气压之间获得适度 CO2压力的能力对于提高反应的产量至关重要。在这些条件下, 主要 (1°) 和二次 (2°) 胺可以 arylated 与电子丰富和电子可怜的芳卤化物。

<table>
	<tbody>
		<tr>
			<td>7.5 mL Sample Vial with Screw Cap (Thermoset)</td>
			<td>Qorpak</td>
			<td>GLC-00984</td>
			<td>Can be reused.</td>
		</tr>
		<tr>
			<td>40 mL Sample Vial with Screw Cap (Thermoset)</td>
			<td>Qorpak</td>
			<td>GLC-01039</td>
			<td>Can be reused.</td>
		</tr>
		<tr>
			<td>Pressure Tube, #15 Thread, 7&#34; Long, 25.4 mm O.D.</td>
			<td>Ace Glass</td>
			<td>8648-06</td>
			<td>Can be reused.</td>
		</tr>
		<tr>
			<td>Pie-Block for 2 Dram Vials</td>
			<td>ChemGlass</td>
			<td>CG-1991-P14</td>
			<td>Can be reused.</td>
		</tr>
		<tr>
			<td>Pie-Block for 10 Dram Vials</td>
			<td>ChemGlass</td>
			<td>CG-1991-P12</td>
			<td>Can be reused.</td>
		</tr>
		<tr>
			<td>3.2 mm PTFE Disposable Stir Bars</td>
			<td>Fisher</td>
			<td>14-513-93</td>
			<td>Can be reused.</td>
		</tr>
		<tr>
			<td>C-MAG HS 7 Control Hotplate</td>
			<td>IKA</td>
			<td>20002695</td>
			<td></td>
		</tr>
		<tr>
			<td>Analytical Weighing Balance</td>
			<td>Sartorius</td>
			<td>QUINTIX2241S</td>
			<td></td>
		</tr>
		<tr>
			<td>Double-Ended Micro-Tapered Spatula</td>
			<td>Fisher Scientific</td>
			<td>21-401-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Hei-VAP Advantage - Hand Lift Model with G5 Dry Ice Condenser Rotary Evaporator</td>
			<td>Heidolph</td>
			<td>561-01500-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Bump Trap 14/20 Joint</td>
			<td>ChemGlass</td>
			<td>CG-1322-01</td>
			<td></td>
		</tr>
		<tr>
			<td>tert-Amyl amine</td>
			<td>Alfa Aesar</td>
			<td>B24639-14</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>2-Methyl-N-(3-methylbenzyl)butan-2-amine</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Prepared from reductive amination of tert-amyl amine and 3-tolualdehyde in the presence of sodium borohydride in methanol.</td>
		</tr>
		<tr>
			<td>Palladium Acetate</td>
			<td>Chem-Impex International, Inc.</td>
			<td>4898</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Silver Trifluoroacetate</td>
			<td>Oakwood Chemicals</td>
			<td>007271</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Phenyl Iodide</td>
			<td>Oakwood Chemicals</td>
			<td>003461</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Acetic Acid</td>
			<td>Fisher Chemical</td>
			<td>A38</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>1,1,1,3,3,3-Hexafluoroisopropanol</td>
			<td>Oakwood Chemicals</td>
			<td>003409</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Deionized Water</td>
			<td></td>
			<td></td>
			<td>Obtained from in-house deionized water system.</td>
		</tr>
		<tr>
			<td>Dry Ice</td>
			<td>Carbonic Enterprises Dry Ice Inc.</td>
			<td></td>
			<td>Non-food grade dry ice.</td>
		</tr>
		<tr>
			<td>Concentrated Hydrochloric Acid</td>
			<td>Fisher Chemical</td>
			<td>A144SI</td>
			<td>Diluted to a 1.2 M solution prior to use.</td>
		</tr>
		<tr>
			<td>Diethyl Ether, Certified</td>
			<td>Fisher Chemical</td>
			<td>E138</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Hexanes, Certified ACS</td>
			<td>Fisher Chemical</td>
			<td>H292</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Saturated Ammonium Hydroxide</td>
			<td>Fisher Chemical</td>
			<td>A669</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Dichloromethane</td>
			<td>Fisher Chemical</td>
			<td>D37</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>Sodium Sulfate, Anhydrous</td>
			<td>Oakwood Chemicals</td>
			<td>044702</td>
			<td>Used as received.</td>
		</tr>
		<tr>
			<td>250 mL Separatory Funnel</td>
			<td></td>
			<td></td>
			<td>Prepared in-house by staff glassblower.</td>
		</tr>
		<tr>
			<td>100 mL Round Bottom Flask</td>
			<td></td>
			<td></td>
			<td>Prepared in-house by staff glassblower.</td>
		</tr>
		<tr>
			<td>Scientific Disposable Funnel</td>
			<td>Caplugs</td>
			<td>2085136030</td>
			<td></td>
		</tr>
		<tr>
			<td>Borosilicate Glass Scintillation Vials, 20 mL</td>
			<td>Fisher Scientific</td>
			<td>03-337-15</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mm O.D. Thin Walled Precision NMR Tubes</td>
			<td>Wilmad</td>
			<td>666000575</td>
			<td></td>
		</tr>
		<tr>
			<td>Chloroform-d</td>
			<td>Cambridge Isotope Laboratories, Inc.</td>
			<td>DLM-7</td>
			<td>Used as received.</td>
		</tr>
	</tbody>
</table>

achieving moderate pressures in sealed vessels using dry ice as a solid co2 source

本文提出了在轻度至中度 CO2压力下, 用干冰进行反应的一般策略。这种技术省却了需要专门的设备来达到适度的压力, 甚至可以用来在更专业的设备和更坚固的反应容器中获得更高的压力。在反应结束时, 瓶子可以很容易地减压在室温下打开。在本例子 CO2担当两个假定的指挥的小组并且方式到钝化胺基体, 从而防止氧化在有机金属反应期间。除了容易添加, 指导组也被排除在真空下, 不需要广泛的净化, 以消除指导组。这一策略允许简便的γ C (sp3) H arylation 脂肪胺, 并有可能被应用于各种其他胺基反应。

遵循这些协议, 有可能向反应瓶收取适量的二氧化碳, 以实现化学反应, 需要 CO2大气。在步骤1中实现的压力计算为大约3大气压 (参见讨论确定这个值), 虽然由于部分溶剂化, 观察到的压力在室温附近2大气压, 应大约2.6 大气在反应条件之下。因此, 在步骤1中的条件下, 2-甲基-4-苯基丁胺可以获得69% 的产量 (图 2)。通过升华 CO2 (步骤 2) 首?...

Watch this Scientific Journal Video about Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source at JoVE.com

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

在这里, 我们提出了一个协议, 以执行反应的简单反应容器在低到中等压力的 CO2。这种反应可以通过在各种容器中进行, 只需以干冰的形式管理二氧化碳, 而不需要昂贵的或精密的设备或装置。

用干冰作为固体 CO2源实现密封容器中的适度压力

Herein is presented a general strategy to perform reactions under mild to moderate CO2 pressures with dry ice. This technique obviates the need for ...

achieving-moderate-pressures-sealed-vessels-using-dry-ice-as-solid

Research

JoVE Journal

Chemistry

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

9.9K 次观看.  University of Toledo. 在这里, 我们提出了一个协议, 以执行反应的简单反应容器在低到中等压力的 CO2。这种反应可以通过在各种容器中进行, 只需以干冰的形式管理二氧化碳, 而不需要昂贵的或精密的设备或装置。

视频: Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry (UPLC-HRMS)

Here we present a workflow to analyze the metabolic profiles for biological samples of interest including; cells, serum, or tissue. The sample is first separated into polar and non-polar fractions by a liquid-liquid phase extraction, and partially purified to facilitate downstream analysis. Both aqueous (polar metabolites) and organic (non-polar metabolites) phases of the initial extraction are processed to survey a broad range of metabolites. Metabolites are separated by different liquid chromatography methods based upon their partition properties. In this method, we present microflow ultra-performance (UP)LC methods, but the protocol is scalable to higher flows and lower pressures. Introduction into the mass spectrometer can be through either general or compound optimized source conditions. Detection of a broad range of ions is carried out in full scan mode in both positive and negative mode over a broad m/z range using high resolution on a recently calibrated instrument. Label-free differential analysis is carried out on bioinformatics platforms. Applications of this approach include metabolic pathway screening, biomarker discovery, and drug development.

Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry UPLC-HRMS

Untargeted metabolomics provides a hypothesis generating snapshot of a metabolic profile. This protocol will demonstrate the extraction and analysis of metabolites from cells, serum, or tissue. A range of metabolites are surveyed using liquid-liquid phase extraction, microflow ultraperformance liquid chromatography/high-resolution mass spectrometry (UPLC-HRMS) coupled to differential analysis software.

不相关的代谢组学，生物源使用超高效液相色谱 - 高分辨质谱（UPLC-HRMS）

Here we present a workflow to analyze the metabolic profiles for biological samples of interest including; cells, serum, or tissue. The sample is first ...

科研

化学

Determining the Ice-binding Planes of Antifreeze Proteins by Fluorescence-based Ice Plane Affinity

Antifreeze proteins (AFPs) are expressed in a variety of cold-hardy organisms to prevent or slow internal ice growth. AFPs bind to specific planes of ice through their ice-binding surfaces. Fluorescence-based ice plane affinity (FIPA) analysis is a modified technique used to determine the ice planes to which the AFPs bind. FIPA is based on the original ice-etching method for determining AFP-bound ice-planes. It produces clearer images in a shortened experimental time. In FIPA analysis, AFPs are fluorescently labeled with a chimeric tag or a covalent dye then slowly incorporated into a macroscopic single ice crystal, which has been preformed into a hemisphere and oriented to determine the a- and c-axes. The AFP-bound ice hemisphere is imaged under UV light to visualize AFP-bound planes using filters to block out nonspecific light. Fluorescent labeling of the AFPs allows real-time monitoring of AFP adsorption into ice. The labels have been found not to influence the planes to which AFPs bind. FIPA analysis also introduces the option to bind more than one differently tagged AFP on the same single ice crystal to help differentiate their binding planes. These applications of FIPA are helping to advance our understanding of how AFPs bind to ice to halt its growth and why many AFP-producing organisms express multiple AFP isoforms.

Antifreeze proteins (AFPs) bind to specific planes of ice to prevent or slow ice growth. Fluorescence-based ice plane affinity (FIPA) analysis is a modification of the original ice-etching method for determination of AFP-bound ice planes. AFPs are fluorescently labeled, incorporated into macroscopic single ice crystals, and visualized under UV light.

通过荧光基冰平面亲和力确定防冻蛋白的冰结合平面

Antifreeze proteins (AFPs) are expressed in a variety of cold-hardy organisms to prevent or slow internal ice growth. AFPs bind to specific planes of ice ...

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. Specifically, the sapphire cell enables visual data collection from multiple loadings to solve a set of material balances to precisely determine phase composition. Ternary phase diagrams can then be established to determine the proportion of each component in each phase at a given condition. In principle, any ternary system can be studied although ternary systems (gas-liquid-liquid) are the specific examples discussed herein. For instance, the ternary THF-Water-CO2 system was studied at 25 and 40&#160;&#176;C and is described herein. Of key importance, this technique does not require sampling. Circumventing the possible disturbance of the system equilibrium upon sampling, inherent measurement errors, and technical difficulties of physically sampling under pressure is a significant benefit of this technique. Perhaps as important, the sapphire cell also enables the direct visual observation of the phase behavior. In fact, as the CO2 pressure is increased, the homogeneous THF-Water solution phase splits at about 2 MPa. With this technique, it was possible to easily and clearly observe the cloud point and determine the composition of the newly formed phases as a function of pressure.
The data acquired with the sapphire cell technique can be used for many applications. In our case, we measured swelling and composition for tunable solvents, like gas-expanded liquids, gas-expanded ionic liquids and Organic Aqueous Tunable Systems (OATS)1-4. For the latest system, OATS, the high-pressure sapphire cell enabled the study of (1) phase behavior as a function of pressure and temperature, (2) composition of each phase (gas-liquid-liquid) as a function of pressure and temperature and (3) catalyst partitioning in the two liquid phases as a function of pressure and composition. Finally, the sapphire cell is an especially effective tool to gather accurate and reproducible measurements in a timely fashion.

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus is a unique tool to study, without sampling, phase behavior under a wide range of pressures. Using a cathetometer, very precise volume measurements can be recorded to measure liquid expansion and phase composition. Thus, this synthetic method enables the study of (1) phase equilibria of multi-component mixtures and (2) the partition behavior of catalyst or model compounds as a function of pressure.

高压蓝宝石细胞对CO的相平衡测量<sub&gt; 2</sub&gt; /有机/水系统

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. ...

Preparing Adherent Cells for X-ray Fluorescence Imaging by Chemical Fixation

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over large or small sample areas. It has been applied in many areas of science, including materials science, geoscience, studying works of cultural heritage, and in chemical biology. In the case of chemical biology, for example, visualizing the metal distributions within cells allows us to study both naturally-occurring metal ions in the cells, as well as exogenously-introduced metals such as drugs and nanoparticles. Due to the fully hydrated nature of nearly all biological samples, cryo-fixation followed by imaging under cryogenic temperature represents the ideal imaging modality currently available. However, under the circumstances that such a combination is not easily accessible or practical, aldehyde based chemical fixation remains useful and sometimes inevitable. This article describes in as much detail as possible in the preparation of adherent mammalian cells by chemical fixation for X-ray fluorescent imaging.

Here, we present a protocol on how to determine the quantity and distribution of metals in a sample using synchrotron X-ray fluorescence. We focus on adherent cells, and describe the chemical fixation method to prepare this sample. We then describe how to mount and image the sample using synchrotron X-rays.

化学固定准备贴壁细胞的X射线荧光成像

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over ...

Real-time Monitoring of Reactions Performed Using Continuous-flow Processing: The Preparation of 3-Acetylcoumarin as an Example

By using inline monitoring, it is possible to optimize reactions performed using continuous-flow processing in a simple and rapid way. It is also possible to ensure consistent product quality over time using this technique. We here show how to interface a commercially available flow unit with a Raman spectrometer. The Raman flow cell is placed after the back-pressure regulator, meaning that it can be operated at atmospheric pressure. In addition, the fact that the product stream passes through a length of tubing before entering the flow cell means that the material is at RT. It is important that the spectra are acquired under isothermal conditions since Raman signal intensity is temperature dependent. Having assembled the apparatus, we then show how to monitor a chemical reaction, the piperidine-catalyzed synthesis of 3-acetylcoumarin from salicylaldehyde and ethyl acetoacetate being used as an example. The reaction can be performed over a range of flow rates and temperatures, the in-situ monitoring tool being used to optimize conditions simply and easily.

Real-time monitoring allows for fast optimization of reactions performed using continuous-flow processing. Here the preparation of 3-acetylcoumarin is used as an example. The apparatus for performing in-situ Raman monitoring is described, as are the steps required to optimize the reaction.

反应执行使用连续流处理的实时监控:3  - 乙酰基香豆素的制备为例

By using inline monitoring, it is possible to optimize reactions performed using continuous-flow processing in a simple and rapid way. It is also possible ...

Measurement of Particle Size Distribution in Turbid Solutions by Dynamic Light Scattering Microscopy

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a technique used to measure the size distribution of polymer solutions or colloidal particles. Although this technique is widely used for the assessment of polymer solutions, it is difficult to measure the particle size in concentrated solutions due to the multiple scattering effect or strong light absorption. Therefore, the concentrated solutions should be diluted before measurement. Implementation of the confocal optical component in a dynamic light scattering microscope1 helps to overcome this barrier. Using such a microscopic system, both transparent and turbid systems can be analyzed under the same experimental setup without a dilution. As a representative example, a size distribution measurement of a temperature-responsive polymer solution was performed. The sizes of the polymer chains in an aqueous solution were several tens of nanometers at a temperature below the lower critical solution temperature (LCST). In contrast, the sizes increased to more than 1.0 &#181;m when above the LCST. This result is consistent with the observation that the solution turned turbid above the LCST.

A protocol for the direct measurement of particle size distribution in concentrated solutions using dynamic light scattering microscopy is presented.

通过动态光散射显微镜混浊解决方案粒度分布的测定

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a ...

Quantifying X-Ray Fluorescence Data Using MAPS

The quantification of X-ray fluorescence (XRF) microscopy maps by fitting the raw spectra to a known standard is crucial for evaluating chemical composition and elemental distribution within a material. Synchrotron-based XRF has become an integral characterization technique for a variety of research topics, particularly due to its non-destructive nature and its high sensitivity. Today, synchrotrons can acquire fluorescence data at spatial resolutions well below a micron, allowing for the evaluation of compositional variations at the nanoscale. Through proper quantification, it is then possible to obtain an in-depth, high-resolution understanding of elemental segregation, stoichiometric relationships, and clustering behavior.
This article explains how to use the MAPS fitting software developed by Argonne National Laboratory for the quantification of full 2-D XRF maps. We use as an example results from a Cu(In,Ga)Se2 solar cell, taken at the Advanced Photon Source beamline 2-ID-D at Argonne National Laboratory. We show the standard procedure for fitting raw data, demonstrate how to evaluate the quality of a fit and present the typical outputs generated by the program. In addition, we discuss in this manuscript certain software limitations and offer suggestions for how to further correct the data to be numerically accurate and representative of spatially resolved, elemental concentrations.

Here, we demonstrate the use of the X-ray fluorescence fitting software, MAPS, created by Argonne National Laboratory for the quantification of fluorescence microscopy data. The quantified data that results is useful for understanding the elemental distribution and stoichiometric ratios within a sample of interest.

利用地图量化 X 射线荧光数据

The quantification of X-ray fluorescence (XRF) microscopy maps by fitting the raw spectra to a known standard is crucial for evaluating chemical ...

Minimum Burning Pressures of Water-based Emulsion Explosives

This manuscript describes a protocol to measure the minimum pressure required for sustained burning of water-based emulsion explosives. Pumping water-based emulsion explosives for blasting applications can be very hazardous, as demonstrated by a number of pump accidents around the globe in the last decades, including some that resulted in fatalities. In Canada, the recognition of this hazard has led to the development of pumping guidelines that were endorsed by both the explosives industry and the Explosive Regulatory Division of the Canadian government. In these guidelines, it was noted that the minimum burning pressures (MBP) measured in a laboratory would provide a good guide to characterize the behaviour of these products in pumping systems. The same guidelines also call for the design of pump systems that prevent, whenever possible, pressures from exceeding the MBP of the product being pumped. At the time of publication of these guidelines, a methodology existed for measuring such MBP values but it had never been validated to measure the MBP of ammonium nitrate water-based emulsions (AWEs). AWEs are now used much more widely than any other water-based explosives and precursors in on-site bulk loading operations.
The Canadian Explosives Research Laboratory (CanmetCERL) has been conducting research over the last ten years to develop a validated testing protocol to measure and interpret representative MBP values for AWEs. The test, as it is performed today, will be described and the critical components will be justified by reference to recent published data. Results of MBP measurements, for a range of AWE products, will be presented. Inclusion of the MBP test in the test standards for the authorization of high explosives in Canada will also be discussed.

We present an apparatus based on hot-wire ignition in a pressurized enclosure and an associated methodology to measure the minimum pressure required to induce sustained combustion in water-based emulsion explosives. This method improves product characterization to allow one to use them more safely during pumping and mixing operations.

水性乳化炸药的最小燃烧压力

This manuscript describes a protocol to measure the minimum pressure required for sustained burning of water-based emulsion explosives. Pumping ...

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of solid-phase synthesis, regenerating Michael (REM) linker strategies, and 1,3-dipolar cycloaddition, a library of structurally similar heterocycles, both with and without a spirocyclic center, can be constructed. The main advantages of the solid-support synthesis are as follows: first, each reaction step can be driven to completion using a large excess of reagents resulting in high yields; next, the use of commercially available starting materials and reagents keep the costs low; finally, the reaction steps are easy to purify via simple filtration. The REM linker strategy is attractive because of its recyclability and traceless nature. Once a reaction scheme is completed, the linker can be reused multiple times. In a typical solid-phase synthesis, the product contains either a part of or the whole linker, which can prove undesirable. The REM linker is &#34;traceless&#34; and the point of attachment between the product and the polymer is indistinguishable. The high diastereoselectivity of the intramolecular 1,3-dipolar cycloaddition is well documented. Limited by the insolubility of the solid support, the reaction progression can only be monitored by a change in the functional groups (if any) via infrared (IR) spectroscopy. Thus, the structural identification of intermediates cannot be characterized by conventional nuclear magnetic resonance (NMR) spectroscopy. Other limitations to this method stem from the compatibilities of the polymer/linker to the desired chemical reaction scheme. Herein we report a protocol that allows for the convenient production of spirocyclic heterocycles that, with simple modifications, can be automated with high-throughput techniques.

Here we present a protocol to demonstrate an efficient method for the synthesis of spirocyclic heterocycles. The five-step process utilizes solid-phase synthesis and regenerating Michael linker strategies. Generally difficult to synthesize, we present a customizable method for the synthesis of spirocyclic molecules otherwise inaccessible to other modern approaches.

[4.4] 刺环氧基的固相合成

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of ...

In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework

In situ infrared spectroscopy is an inexpensive, highly sensitive, and selective valuable tool to investigate the interaction of polycrystalline solids with adsorbates. Vibrational spectra provide information on the chemical nature of adsorbed species and their structure. Thus, they are very useful for obtaining molecular level understanding of surface species. The IR spectrum of the sample itself gives some direct information about the material. General conclusions can be drawn concerning hydroxyl groups, some stable surface species and impurities. However, the spectrum of the sample is &#34;blind&#34; with respect to the presence of coordinatively unsaturated ions and gives rather poor information about the acidity of surface hydroxyls, species decisive for the adsorption and catalytic properties of the materials. Furthermore, no discrimination between bulk and surface species can be made. These problems are solved by the use of probe molecules, substances that interact specifically with the surface; the alteration of some spectral features of these molecules as a result of adsorption provides valuable information about the nature, properties, location, concentration, etc., of the surface sites.
The experimental protocol for in-situ IR studies of gas/sample interaction includes preparation of a sample pellet, activation of the material, initial spectral characterization through the analysis of the background spectra, characterization by probe molecules, and study of the interaction with a particular set of gas mixtures. In this paper we investigate a zirconium terephthalate metal organic framework, Zr6O4(OH)4(BDC)6 (BDC = benzene-1,4-dicarboxylate), namely UiO-66 (UiO refers to University of Oslo). The acid sites of the UiO-66 sample are determined by using CO and CD3CN as molecular probes. Furthermore, we have demonstrated that CO2 is adsorbed on basic sites exposed on dehydroxylated UiO-66. Introduction of water to the system produces hydroxyl groups acting as additional CO2 adsorption sites. As a result, CO2 adsorption capacity of the sample is strongly enhanced.

In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework

The use of FTIR spectroscopy for investigation of the surface properties of polycrystalline solids is described. Preparation of sample pellets, activation procedures, characterization with probe molecules and model studies of CO2 adsorption are discussed.

原位FTIR 光谱作为气体/固体相互作用研究工具:UiO-66 金属-有机框架中的水增强 CO2吸附

In situ infrared spectroscopy is an inexpensive, highly sensitive, and selective valuable tool to investigate the interaction of polycrystalline solids ...