我们感谢太平洋西北国家实验室 (4500亿) 核过程科学倡议 (NPSI)-实验室定向研究和发展基金 (LDRD) 的支持。Dr. Sayandev 查特吉提供了合成的石粒子。通过格雷斯威利环境分子科学实验室 (emsl-lv) 的一般用户提案提供了仪器接入。emsl-lv 是一个由生物和环境研究办公室 (BER) 在4500亿主办的国家科学用户设施。4500亿由巴特尔在合同 DE-AC05-76RL01830 下经营。

1. 准备 AlOOH 液体样品 注意: 不要徒手触摸扫描电镜室内的标本或任何东西。在处理 chomiak-salvi 装置时, 应随时佩戴无粉手套, 并将其安装到 SEM 阶段, 以避免表面分析过程中的潜在污染. 
<ol> <li> 制作 AlOOH 库存解决方案 (1 毫克/毫升) <ol> <li> 将10毫克的 AlOOH 粉末溶解在10毫升的 DI 水中, 以使1毫克/毫升 AlOOH 库存解决方案. </li>
		<li> Ultrasonicate 5 分钟的库存解决方案 
		注: 该股票溶液的 ph 值约为 4.6, 用 ph 计测量。pH 值的解决方法在这项工作中没有被调整和使用. </li>
	</ol> </li> <li> 使稀释的解决方案为10和 #181; g/ml <ol> <li> 将1毫克/毫升 AlOOH 库存解决方案稀释到10和 #181; 通过吸管将1毫升分配到99毫升的水中, 克/毫升. </li>
		<li> Ultrasonicate 5 分钟的解决方案 
		注: 溶液的 ph 值约为 5.8, 经稀释后 ph 计测定. </li>
	</ol> </li> </ol> 2。溅射涂层 chomiak-salvi 的罪孽膜窗口与碳 <ol> <li> 将碳棒插入拉杆夹. 
	注: 杆架可识别为附着在铰接盖上的工件. </li>
	<li> 使用一双镊子, 并小心地把胶带放在 chomiak-salvi 和 #39 上; s 型膜窗框. 
	注: 该胶带用于在表面分析前保护原罪膜. </li>
	<li> 使用碳带将 chomiak-salvi 装置固定在碳涂布机室内, 在涂布机的舞台上安装 chomiak-salvi 装置的聚四氟乙烯油管。关上盖子. </li>
	<li> 按 #34;P 功率和 #34; 启动真空泵的按钮. </li>
	<li> 按 #34、电压和 #34; 在碳涂布机前面板上的按钮, 通过调整 (和 #9650;) 和下 (和 #9660;) 按钮, 将值设置为 4.6 V. 
	注: 由于各种碳机, 电压设置可能会有所不同. </li>
	<li> 通过切换 #34;P 功率和 #34 打开涂层厚度监视器; 按钮。清除屏幕中显示的读数 #34; 厚度 (nm) 和 #34; 按下按钮和 #34; 零和 #34; 如果读数不是零, 则为零。按 #34; 计时器和 #34; 在碳涂布机和 #39 的前面板上, 通过调整 (和 #9650;) 和 #9660 按钮, 将沉积时间设置为三十年代. </li>
	<li> 通过切换按钮和 #34、自动和 #9668、#9658、手动和 #34、#34、自动和 #34 等方式, 将碳素涂布机和 #39 的操作模式自动保存;开关 #34; 启动/停止和 #34; 按钮 #34; 启动和 #34; 当真空达到约4和 #215; 10 -4 毫巴, 由碳涂布机和 #39 前面板上的真空计测量. </li>
	<li> 一旦厚度监视器显示碳涂层已达到 20 nm, 请按 #34; 停止和 #34; 按钮以终止涂层过程并释放真空密封. </li>
	<li> 在处理设备时使用乙烯基手套打开盖子并取出碳涂层 chomiak-salvi 装置. 
	注: 在样品上涂上碳后, 在试样上形成导电层, 以抑制充电效果, 改善扫描电镜成像所需的 SE 信号。将涂敷的设备安全地存放在带有盖子的干净培养皿中, 直到设备准备好安装在 SEM 阶段。为了保证膜的涂层充分, 建议在涂布后目视检查设备。如果涂层不够厚, 第二次溅射涂层可以应用到厚度测量, 直到 10 nm. </li>
</ol> 3。安装该装置并使用扫描电镜/聚焦离子束 (纤维蛋白原) 在 chomiak-salvi 的单片上制作孔径, 使用 <ol> <li> 打开 sem 标本室 <ol> <li> 打开 sem 仪器控制计算机上的相关显微镜控制软件. 
		注: 控制软件可能因各种中小型公司而异. </li>
		<li> 通过单击和 #34 打开标本室; 排气和 #34; 在与 #34 相关联的显微镜控制软件的图形用户界面 (GUI) 上; 光束控制和 #34; tab, 以便开箱门. </li>
		<li> 小心打开舱门 (一旦排气完成). </li>
	</ol> </li> <li> 将 chomiak-salvi 设备安装到 SEM 阶段 注: 检查 SiN 膜的表面, 看它是完好的还是在安装前使用光学显微镜。在扫描电镜台上安装的 chomiak-salvi 装置不能触及试样室内的 Everhart Thornley 探测器。
	<ol> <li> 选择标准的 SEM 样品夹存根。使用适当的螺栓和六角扳手将存根固定到舞台中心. </li>
		<li> 在存根上放置两条双面碳带. </li>
		<li> 将 chomiak-salvi 装置粘在放置在存根上的碳带上, 并朝上. </li>
		<li> 使用额外的两条单面铜带将 chomiak-salvi 固定在存根上, 将 chomiak-salvi 硅橡胶块固定在 SEM 金属存根上。此外, 使用铜带连接犯罪框架和金属存根。请确保磁带没有完全覆盖原罪膜. 
		注: 使用碳和铜带有助于确保在扫描电镜测量期间从 SiN 膜中除去电荷的连续接地路径。胶带在 SiN 框架边缘的位置非常重要, 因为它确保了接地, 并在分析过程中减少了充电。该装置的底部还必须与 SEM 存根通过双面碳带完全接触。胶带不能覆盖的罪孽膜, 以避免可能损坏的处理. </li>
	</ol> </li> <li> 沿着标本室 <ol> 关闭标本室门。选择 #34; 高真空和 #34; 在 #34 下的 SEM 软件 GUI 模式; 光束控制和 #34; 页. </li>
		<li> 单击 #34;P 人民人民联盟和 #34; #34 上的按钮; 光束控制和 #34; 页面开始清空, 并通过手动将压力施加到会议厅门, 直到建立了所需的真空. 
		注: 腔室压力必须达到至少1.0 和 #215; 10 -5 乇, 在成像前必须稳定保持在或低于此值。这是一个重要的步骤, 使高分辨率的解决方案的成像。可以从 GUI 的右角监视压力设置. </li>
	</ol> </li> <li> 通过单击工具栏上的 "#34";P "#34" 来激活电子束成像区域, 从而在 SiN 膜中使用光圈 <ol> <li>。通过单击 #34 打开电子束, #34 上的横梁和 #34 上的按钮; 光束控制和 #34; 页面。从 #34;D etectors 和 #34 中选择离地探测器和 SE 模式; 下拉菜单. 
		注: 由于不同的中小企业配置, 检测器可能会有所不同。镜头内检测器也适用于液体扫描电镜分析. </li>
		<li> 将 Z 坐标值链接到实际的e 工作距离 (前进) 的价值, 通过单击 #34; 链接和 #34; 工具栏上的图标。将工作距离 (WD) 设置为 10 mm, 将数字10输入到坐标和 #34 的文本框中; Z 和 #34; 在和 #34; 导航和 #34; 页时, #34; 实际和 #34; 选择距离. 
		注: WD 可能因各种中小型公司而异. </li>
		<li> 将电子束电流设置为 0.47 nA, 加速电压为8电子伏特, 分辨率为1024和 #215; 884 从相应的列表框中显示在工具栏上的电子束成像区域. 
		注: 电流和电压设置可能因不同的中小企业而异. </li>
		<li> 将微通道 (0.2 mm x 1.5 mm) 扭曲 #34; x 和 #34; 和 #34; Y 和 #34; 手动用户界面 (MUI) 板上的 shift 旋钮, 以观察控制监视器上的实时图像。用鼠标从一端到另一个端, 绘制一条与微通道平行的线。单击和 #34; xT 对齐特征和 #34; 从下拉菜单中 #34; 阶段和 #34; 工具栏上的选项卡, 选择和 #34; 水平和 #34; 使微通道对齐. </li>
		<li> 将舞台倾斜设置为0和 #176; 通过从 "和" #34 中选择值; T 和 #34; #34 上的列表框; 导航和 #34; 页。在微通道附近找到一个独特的粒子特征, 并将其置于黄十字下, 通过移动舞台, 使用 #34; X 和 #34; 和 #34; Y 和 #34; shift 旋钮。将特征放大至 1,000X, 并扭曲 #34; 对比度和 #34; #34; 亮度和 #34; #34; 粗 #34; #34; 精细 #34; 在 MUI 上的旋钮, 以优化粒子特征的图像. </li>
		<li> 将舞台倾斜到15和 #176; 通过从 "和" #34 中选择值; T 和 #34; #34 上的列表框; 导航和 #34; 页。使用和 #34; Z 控制和 #34; 通过按下鼠标上的滚轮, 并在舞台倾斜后, 在电子束成像区域的屏幕上将特征拖回黄色十字。
		<ol> <li> 再次将舞台倾斜到30和 #176; 然后使用 "#34"、"Z 控制" 和 "#34" 将特征带回到交叉处;。将舞台向后倾斜到0和 #176; 观察特征的位置;如果特征没有显著变化, 则 eucentric 高度被确认. 
			注: 对 eucentric 高度进行定位, 以保持离子束和电子束聚焦在同一位置, 从而达到良好的铣削精度。如果在将舞台向后倾斜到0和 #176 时, 重复步骤3.4.6 的过程;。eucentric 高度应调整为每个新安装的样品, 以最大的准确性. </li>
		</ol> </li> <li> 将舞台倾斜到52和 #176; 通过从 "和" #34 中选择值; T 和 #34; #34 上的列表框; 导航和 #34; 页. 
		注: 倾斜程度可能因各种中小型公司而异. </li>
		<li> 停用 #34;P 因和 #34; 通过单击按钮来确保离子束成像区域处于激活的图标上。通过点击和 #34 打开镓源离子束; 横梁; #34; #34; 光束控制和 #34; 页。
		<ol> <li> 通过从位于工具栏上的相应电压和当前列表框中选择这些值, 将离子束的加速电压设置为30电子伏特和 0.3 nA 的电流。将微通道带到这个成像区的中心. </li>
		</ol> </li> <li> 通过从 #34;P attern 和 #34 的列表框中选择此功能, 并在 #34;P atterning 和 #34; 页中选取此项作为模式。设置 #34; 外径和 #34; 1 和 #181; #34; 内径和 #34; 0 和 #181; m, #34; Z 大小和 #34; 到 500 nm, #34;D 井时间和 #34; 到1和 #181; 在相应的文本框中。
		<ol> <li> 类型和 #34; Si 和 #34; 在和 #34; 应用程序和 #34; 文本框因为 about-to-be 的检测窗口的主要组件是氮化硅。然后单击 #34;P atterning 菜单/开始模式和 #34; 按钮开始铣削覆盖微通道的检测窗口上的孔。多次重复铣削过程以获得一系列圆孔。在一个实验中, 可能会有几个漏洞. 
			注: 孔是100和 #181; m 分开, 从微通道的一边到另一个。快速移动, 以减少在犯罪膜上的光束损伤。扫描电镜下的铣削过程通常从微通道的左、右两个方向开始, 以方便地跟踪和编号。运营商可以选择从底部或顶部取决于频道的方向和个人偏好。确保扫描电镜下的铣削完成并充分, 以便能在孔内探测到试样. </li>
		</ol> </li> </ol> </li> <li> 在扫描电镜/心室颤动 <ol> <li> 后将舞台倾斜回0和 #176; 通过从 #34 中选择 0; T 和 #34; #34 上的列表框; 导航和 #34; 页。通过点击和 #34 关闭电子束和离子束; 光束和 #34; 当相应的波束成像区域被激活。点击和 #34; 排气和 #34; 在和 #34; 光束控制和 #34; 页面以释放标本室. </li>
	</ol> </li> </ol> 4。用液体样本加载 chomiak-salvi <ol> <li> 清除 chomiak-salvi 使用 DI 水 <ol> <li> 在完全通风后打开扫描电镜室门, 并在舞台上保留 chomiak-salvi 设备. 
		注意: 为了节省安装设备和对焦的时间, 强烈建议在加载示例时将设备放在舞台上. </li>
		<li> 将1毫升的水抽入无菌注射器, 将注射器与微流控装置的入口连接, 使用聚四氟乙烯导管接头, 然后缓慢地将液体注入 3-5 分钟. 
		注: 在需要注射溶液到 chomiak-salvi 的所有步骤中, 推荐使用注射器泵。这一步可以做到这一点, 通过设置一个1毫升无菌注射器包含解决方案的流速为 100-250 和 #181; L/分钟. 利用注射器泵在恒定流速的情况下, 可以减少损害的可能性, 犯罪膜. </li>
		<li> 重复步骤4.1.2 三次, 使用 1 ml 10 和 #181; 在步骤1中准备的 g/ml AlOOH, 以确保样品的浓度不会被预加载的 DI 水稀释. </li>
		<li> 注射后, 取出注射器。使用聚醚醚酮联合连接 chomiak-salvi 的入口和出口。用实验室湿巾在 chomiak-salvi 外干燥任何液体。如果聚四氟乙烯导管或微通道内有气泡, 请重做 AlOOH 样品注入, 直到聚四氟乙烯导管内没有气泡. 
		注: 用手指拧紧聚醚醚酮联合。在收紧联合时不要使用太多的强度, 以免在 chomiak-salvi 装置内产生明显的内部压力增加, 这会导致对原罪膜的损害. 
		注: 微通道内的气泡可能会影响扫描并导致图像 shift.设备外的任何液体都会影响真空状态, 因此在将其插入真空室之前, chomiak-salvi 和聚四氟乙烯管的外部应彻底干燥。另外, 设备不应该有物理损伤 ( 例如 , 切开在管子, 残破的罪孽膜窗口) 导致漏。否则, 腔室压力可能达不到所需的高真空, 气泡可能在油管中形成, 而液体样品将在吸尘过程中丢失. </li>
	</ol> </li> </ol> 5。进行液体扫描电镜成像和元素分析 <ol> <li> 使用 "检测器" 和 "SE 模式 <ol> <li> 关闭标本室门拍摄图像。选择 #34; 高真空和 #34; 在 #34 下的 SEM 软件 GUI 模式; 光束控制和 #34; 页面。单击 #34;P 人民人民联盟和 #34; #34 上的按钮; 光束控制和 #34; 页面开始清空并将手压施加到室内门, 直到建立了所需的真空. </li>
		<li> 激活电子束成像区域, 单击 #34;P 因和 #34; 工具栏上的图标。通过单击 #34 打开电子束, #34 上的横梁和 #34 上的按钮; 光束控制和 #34; 页面。从 #34;D etectors 和 #34 中选择检测器和图像的 SE 模式; 下拉菜单。
		<ol> <li> 将在电子束成像区的 GUI 工具栏上显示的相应列表框中, 将加速电压设置为8电子伏特, 并将电流从 0.47 nA 调到当前值。通过键入数字和 #34; 7 和 #34, 将 WD 设置为 7 mm; 在坐标和 #34 的文本框中; Z 和 #34; 在和 #34; 导航和 #34; #34; 实际和 #34; 选择距离. 
			注: 梁电压、电流和工作距离的参数可能因不同的中小企业而异. </li>
		</ol> </li> <li> 将该功能放大到1000和 #215; 并将 #34; 对比度和 #34;; #34; 亮度和 #34;; #34; 粗 #34; #34; 精细和 #34; 在 MUI 上的旋钮优化粒子特征的图像. </li>
		<li> 将电子束成像区的活图像中的第一个孔旋转 #34; X 和 #34; 和 #34; Y 和 #34; 在 MUI 板上的 shift 旋钮。放大图像与粒子放大20万和 #215; 通过扭 #34; 放大和 #34; 旋钮在梅板。从工具栏上的列表框中选择屏幕分辨率和 #34; 1024 和 #215; 884 和 #34; </li>
		<li> 从工具栏上的列表框中将扫描速率设置为30和 #181;按 F4 键以拍摄电子束成像区中显示的当前图像的快照. </li>
		<li> 按 ctrl+ S 键将图像作为. tif 文件保存到所需位置, 并使用已定义的文件名 (包括增量数字). </li>
		<li> 通过扭曲 #34 缩放, 放大和 #34; 旋钮定位下一个相邻的孔。重复操作步骤 5.1.4-5.1.6, 以图像的 AlOOH 粒子在其余的孔. </li>
	</ol> </li> <li> 进行元素分析使用 EDX <ol> <li> 将能量色散光谱学 (EDS) 探测器插入会议厅。
		<li> 在电子束成像区域上, 选择显微镜控制显示器和 SE 模式下的测向探测器。将加速电压设置为8凯文, 电流到 0.47 nA, WD 到 7 mm, 如步骤5.1.2 所述. </li>
		<li> 将每个孔中的 AlOOH 粒子放大200,000X 放大和 #34; 放大和 #34; 在 MUI 板上的旋钮. 
		注意: 将电子束聚焦在同一个点上, 以提供更多的局部元素信息。 图 1a 中提供了 AlOOH 的图像. </li>
		<li> 打开关联的 EDAX 软件. 
		注意: 由于不同的仪器和 #39, 相关的软件可能会有所不同; 配置. </li>
		<li> 单击和 #34; 开始记录新的光谱和 #34; 在用户界面 (UI) 中收集 EDX 频谱。选择和 #34;P 讲 ID 和 #34; 选择频谱的可能元素。在观察到的元素中键入 例如 , 在这种情况下, 将氧气放入 #34; 元素和 #34; 字段。单击并 #34; 添加和 #34; 将元素应用于频谱. </li>
		<li> 单击并 #34; 文件和 #34; 然后单击并 #34; 另存为 #34;。使用所需的文件名保存. csv 格式的频谱数据, 以便使用图形软件进行进一步绘图. </li>
		<li> 在步骤 5.3.3 5.3.6 中重复操作, 以记录每个孔的 EDX 频谱. </li>
		<li> 在完成每个孔的成像和频谱记录后, 通过单击和 #34 来关闭电子束; 横梁和 #34; #34 上的按钮; 光束控制和 #34; 电子束成像区域打开时的页面。通过点击和 #34, 排气孔和 #34, 在同一页上的扫描电镜室。在舱门打开后, 取出所有的带子, 小心地把样品从舞台上取下. </li>
		<li> 重复使用 DI 水和空微通道进行控制实验的过程. </li>
	</ol> </li> </ol> 6。绘制 EDX 频谱 <ol> <li> 将. csv 频谱文件导入到图形软件中. </li>
	<li> 使用能级作为 x 轴的图象, 并通过 EDX 作为 y-axis 来显示重建的光谱来绘制光谱, 如图 2a 、2b 和 2c 。
</ol>

<ol>
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作者没有什么可透露的。

SEM 是一种功能强大的技术在表面表征的有机和无机材料的纳米 (nm) 水平高分辨率1。例如, 它被广泛用于分析固体和干燥样品, 如地质材料26和半导体27。然而, 由于在电子显微镜1所需的高度真空环境中液体的不相容性, 它对湿和液体样品的定性有局限性。SEM 样品制备通常需要脱水或 freeze-drying 的水合标本, 特别是生物标本<sup cl...

扫描电子显微镜 (SEM) 被广泛应用于研究各种标本的高分辨率成像1。与 SEM 相关的能量色散 x 射线光谱 (EDX) 能够测定元素组成1。传统上, SEM 是用于成像只有干和固体样品。在过去30年中, 开发了环境扫描电镜 (镜) 分析的部分水合样品在蒸汽环境2,3,4,5。然而, 镜无法图像的湿, 完全流体样品与理想的高分辨率6。用 sem7,8对湿法样品进行了扫描电镜成像。然而, 这些细胞主要开发为生物标本和散射电子成像, 并且为应用是更容易接近的为那些设计9,10。
为了解决在使用 SEM 分析其本机液态环境中的各种样品时所面临的挑战, 我们发明了一种真空兼容微流控装置, 用于在液体真空界面 (chomiak-salvi) 上进行分析, 以使高空间分辨率的次级用扫描电镜中的高真空模式对液体样品进行电子 (SE) 成像和元素分析。这项新技术包括以下独特的特点: 1) 液体在直径为 1-2 µm 的小孔径中直接探测;2) 液体通过表面张力在孔内举行;和 3) chomiak-salvi 是便携的, 可以适应多个分析平台11,12,13,1415,16,17 ,18。
chomiak-salvi 由100纳米厚的氮化硅 (SiN) 膜和200µm 宽的微通道组成, 由烷 (矽) 块制成。应用原膜窗口密封微通道。在以前的论文和专利11、19、20中详细介绍了制造细节和关键设计考虑事项。目前, 一家领先的显微镜耗材制造商和分销商已经购买了销售 chomiak-salvi 设备的许可证, 以商用的液体扫描电镜应用21,22。
chomiak-salvi 在 vacuum-based 分析仪器中的应用已被证明使用各种水溶液和复杂的液体混合物, 包括生物膜, 哺乳动物细胞, 纳米粒子和电极材料12,14,17,20,23,24. 然而, 上述工作大多采用飞行时间二次离子质谱法作为关键的分析工具, 因此尚未充分探讨液体 chomiak-salvi 扫描电镜的应用. 在这项工作中, chomiak-salvi 已被用来研究更大的非胶体微粒液体利用 SEM 成像和 EDX 元素分析。样品由我们实验室合成的 AlOOH 颗粒组成。Submicrometer-sized 石颗粒是已知的高放射性废物在汉福德网站上存在。它们是缓慢的溶解, 并可能导致流变问题的废物处理。因此, 有能力在液体25中表征石粒子是很重要的。这种技术方法可用于研究石在各种物理化学条件下, 以提高对这些微粒和相关流变特性的认识。为了研究悬浮在液体中的颗粒, 利用这些粒子 step-by 了如何将 chomiak-salvi 应用到高真空扫描电镜中。文中重点介绍了 chomiak-salvi 和 sem 集成以及 sem 数据采集的关键技术要点。
该协议提供了液体样品分析使用 chomiak-salvi 和液体 sem 成像, 对于那些谁有兴趣利用这一新技术在不同应用的液体 sem 在未来的演示。

<table width="2033">
	<tbody>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Carbon Coater</td>
			<td style="width:311px;">Cressington</td>
			<td style="width:196px;">208 Carbon</td>
			<td style="width:1237px;">It is accompanied with thickness monitor MTM-10.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">SEM</td>
			<td style="width:311px;">FEI</td>
			<td>Quanta 3D FEG</td>
			<td style="width:1237px;">It provides highly resolved scanning electron microscopy and elemental analysis.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">System for Analysis at the Liquid Vacuum Interface (SALVI)</td>
			<td style="width:311px;">Pacific Northwest National Laboratory</td>
			<td>N/A</td>
			<td style="width:1237px;">SALVI is a unique, vacuum compatible microfluidic cell that enables the characterization of the liquid sample using vacuu- based scientific instrument.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">PEEK Union</td>
			<td style="width:311px;">Valco</td>
			<td>ZU1TPK</td>
			<td>The polyether ether ketone union is used for connecting the inlet and outlet of SALVI</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Syringe</td>
			<td style="width:311px;">BD</td>
			<td>309659</td>
			<td style="width:1237px;">1 mL</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Pipette</td>
			<td style="width:311px;">Thermo Fisher Scientific</td>
			<td>21-377-821</td>
			<td style="width:1237px;">Range: 100 to 1,000 mL</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Pipette Tip 1</td>
			<td style="width:311px;">Neptune</td>
			<td>2112.96.BS</td>
			<td style="width:1237px;">1,000 &#181;L</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Pipette Tip 2</td>
			<td style="width:311px;">Rainin</td>
			<td>17001865</td>
			<td style="width:1237px;">20 &#181;L</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Syringe Pump</td>
			<td style="width:311px;">Harvard Apparatus</td>
			<td>70-2213</td>
			<td style="width:1237px;">It is used to inject the liquid sample into the SALVI device.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">pH meter</td>
			<td style="width:311px;">Fisher Scientific/accumet</td>
			<td>13-636-AP72</td>
			<td style="width:1237px;">It is used for measuring the pH of AlOOH in DI water.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Barnstead Ultrapure Water System, UV/UF</td>
			<td style="width:311px;">Thermo Scientific Barnstead</td>
			<td style="width:196px;">Nanopure diamond D11931</td>
			<td style="width:1237px;">It is used for producing DI water.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Centrifuge tubes</td>
			<td style="width:311px;">Fisher scientific/Falcon</td>
			<td>15-527-90</td>
			<td style="width:1237px;">15 mL</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Bransonic ultrasonic cleaner</td>
			<td style="width:311px;">Sigma-Aldrich</td>
			<td>2510</td>
			<td style="width:1237px;">It is used to ultrasonicate the AlOOH liquid sample.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">Balance</td>
			<td style="width:311px;">Mettler Toledo</td>
			<td>11106015</td>
			<td style="width:1237px;">XS64</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:289px;height:20px;">AlOOH</td>
			<td style="width:311px;">Pacific Northwest National Laboratory</td>
			<td>N/A</td>
			<td style="width:1237px;">It is synthesized by scientists at Pacific Northwest National Laboratory.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">xT microscope Control</td>
			<td>FEI</td>
			<td>Quanta 3D FEG</td>
			<td>Default microscope control software of SEM Quanta 3D FEG</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EDAX Genesis software</td>
			<td style="width:311px;">EDAX</td>
			<td>N/A</td>
			<td style="width:1237px;">The software is used for collecting the EDX elemental information of the samples.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:289px;height:21px;">Teflon tubing</td>
			<td>SUPELCO</td>
			<td>58697-U</td>
			<td style="width:1237px;">It is used for introducing the sample into the microchannel and holding adequate volume of liquid.</td>
		</tr>
	</tbody>
</table>

in situ characterization of boehmite particles in water using liquid sem

原位水中石 (AlOOH) 粒子的成像和元素分析是利用系统进行液体真空界面 (chomiak-salvi) 和扫描电子显微镜 (SEM) 的分析而实现的。本文介绍了将真空相容 SAVLI 与扫描电镜相结合, 获得高真空液中颗粒的二次电子 (SE) 图像的方法和关键步骤。能量色散 x 射线光谱学 (EDX) 用于获得液体和控制样品中的颗粒元素分析, 包括只去离子水和空通道。合成的石 (AlOOH) 颗粒悬浮在液体中作为一个模型在液体 SEM 插图。结果表明, 粒子可以在 SE 模式下成像, 分辨率很好 (即, 400 nm)。与 DI 水和空通道控制相比, AlOOH EDX 谱显示了铝 (Al) 的显著信号。原位液体扫描电镜是一种强有力的技术来研究液体中的微粒与许多令人兴奋的应用。本程序旨在提供技术 know-how, 以进行液体扫描电镜成像和 EDX 分析使用 chomiak-salvi 和减少潜在的陷阱时, 使用这种方法。

介绍了用原位液体扫描电镜与 EDX 相结合的方法对颗粒进行成像和分析的结果。结果包括硒图像和 EDX 谱。SE 图像在图 1中的100,000X 和200,000X 放大级别获得。图 1a描述了 AlOOH 的 SE 图像,图 1b DI 水, 以及图 1c空通道中的孔。应用 SE 的8伏加速电压和 0.47 nA 光束电流, 得到了图像。使...

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In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

原位水中石粒子的液体扫描电镜表征

本文采用原位液体扫描电子显微镜对去离子水中的石颗粒进行 real-time 成像和元素组成分析。

In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface ...

in-situ-characterization-boehmite-particles-water-using-liquid

Research

JoVE Journal

Chemistry

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

9.1K 次观看.  Pacific Northwest National Laboratory. 本文采用原位液体扫描电子显微镜对去离子水中的石颗粒进行 real-time 成像和元素组成分析。

视频: In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

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

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp2 carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail.

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

A protocol is described for the characterization of the key electrochemical parameters of a boron doped diamond (BDD) electrode and subsequent application for in situ pH generation experiments.

掺硼金刚石电极质量和应用，以评估<em&gt;原位</em&gt;本地pH值通过水电改造

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended ...

Synthesis and Exfoliation of Discotic Zirconium Phosphates to Obtain Colloidal Liquid Crystals

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and engineers. Growth of such anisotropic nanocrystals through a simple chemical method is a challenging task. In this study, we fabricate discotic nanodisks of zirconium phosphate [Zr(HPO4)2&#183;H2O] as a model material using hydrothermal, reflux and microwave-assisted methods. Growth of crystals is controlled by duration time, temperature, and concentration of reacting species. The novelty of the adopted methods is that discotic crystals of size ranging from hundred nanometers to few micrometers can be obtained while keeping the polydispersity well within control. The layered discotic crystals are converted to monolayers by exfoliation with tetra-(n)-butyl ammonium hydroxide [(C4H9)4NOH, TBAOH]. Exfoliated disks show isotropic and nematic liquid crystal phases. Size and polydispersity of disk suspensions is highly important in deciding their phase behavior.

A two dimensional model material of discotic zirconium phosphate was developed. The inorganic crystal with lamellar structure was synthesized by hydrothermal, reflux, and microwave-assisted methods. On exfoliation with organic molecules, layered crystals can be converted to monolayers, and nematic liquid crystal phase was formed at sufficient concentration of monolayers.

合成与盘状磷酸盐锆剥落获取胶体液晶

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and ...

Radiolabeling and Quantification of Cellular Levels of Phosphoinositides by High Performance Liquid Chromatography-coupled Flow Scintillation

Phosphoinositides (PtdInsPs) are essential signaling lipids responsible for recruiting specific effectors and conferring organelles with molecular identity and function. Each of the seven PtdInsPs varies in their distribution and abundance, which are tightly regulated by specific kinases and phosphatases. The abundance of PtdInsPs can change abruptly in response to various signaling events or disturbance of the regulatory machinery. To understand how these events lead to changes in the amount of PtdInsPs and their resulting impact, it is important to quantify PtdInsP levels before and after a signaling event or between control and abnormal conditions. However, due to their low abundance and similarity, quantifying the relative amounts of each PtdInsP can be challenging. This article describes a method for quantifying PtdInsP levels by metabolically labeling cells with 3H-myo-inositol, which is incorporated into PtdInsPs. Phospholipids are then precipitated and deacylated. The resulting soluble 3H-glycero-inositides are further extracted, separated by high-performance liquid chromatography (HPLC), and detected by flow scintillation. The labeling and processing of yeast samples is described in detail, as well as the instrumental setup for the HPLC and flow scintillator. Despite losing structural information regarding acyl chain content, this method is sensitive and can be optimized to concurrently quantify all seven PtdInsPs in cells.

Phosphoinositides are signaling lipids whose relative abundance rapidly changes in response to various stimuli. This article describes a method to measure the abundance of phosphoinositides by metabolically labeling cells with 3H-myo-inositol, followed by extraction and deacylation. Extracted glycero-inositides are then separated by high-performance liquid chromatography and quantified by flow scintillation.

放射性标记和磷酸肌醇的细胞水平的定量高效液相色谱耦合流动闪烁

Phosphoinositides (PtdInsPs) are essential signaling lipids responsible for recruiting specific effectors and conferring organelles with molecular ...

In Situ Characterization of Hydrated Proteins in Water by SALVI and ToF-SIMS

This work demonstrates in situ characterization of protein biomolecules in the aqueous solution using the System for Analysis at the Liquid Vacuum Interface (SALVI) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The fibronectin protein film was immobilized on the silicon nitride (SiN) membrane that forms the SALVI detection area. During ToF-SIMS analysis, three modes of analysis were conducted including high spatial resolution mass spectrometry, two-dimensional (2D) imaging, and depth profiling. Mass spectra were acquired in both positive and negative modes. Deionized water was also analyzed as a reference sample. Our results show that the fibronectin film in water has more distinct and stronger water cluster peaks compared to water alone. Characteristic peaks of amino acid fragments are also observable in the hydrated protein ToF-SIMS spectra. These results illustrate that protein molecule adsorption on a surface can be studied dynamically using SALVI and ToF-SIMS in the liquid environment for the first time.

In Situ Characterization of Hydrated Proteins in Water by SALVI and ToF-SIMS

This work presents a protocol for liquid handling and sample introduction to a microchannel for in situ time-of-flight secondary ion mass spectrometry analysis of protein biomolecules in an aqueous solution.

在水中水合蛋白原位表征SALVI和TOF-SIMS

This work demonstrates in situ characterization of protein biomolecules in the aqueous solution using the System for Analysis at the Liquid Vacuum ...

Sequencing of Plant Wall Heteroxylans Using Enzymic, Chemical (Methylation) and Physical (Mass Spectrometry, Nuclear Magnetic Resonance) Techniques

This protocol describes the specific techniques used for the characterization of reducing end (RE) and internal region glycosyl sequence(s) of heteroxylans. De-starched wheat endosperm cell walls were isolated as an alcohol-insoluble residue (AIR)1 and sequentially extracted with water (W-sol Fr) and 1 M KOH containing 1% NaBH4 (KOH-sol Fr) as described by Ratnayake et al. (2014)2. Two different approaches (see summary in Figure 1) are adopted. In the first, intact W-sol AXs are treated with 2AB to tag the original RE backbone chain sugar residue and then treated with an endoxylanase to generate a mixture of 2AB-labelled RE and internal region reducing oligosaccharides, respectively. In a second approach, the KOH-sol Fr is hydrolyzed with endoxylanase to first generate a mixture of oligosaccharides which are subsequently labelled with 2AB. The enzymically released ((un)tagged) oligosaccharides from both W- and KOH-sol Frs are then methylated and the detailed structural analysis of both the native and methylated oligosaccharides is performed using a combination of MALDI-TOF-MS, RP-HPLC-ESI-QTOF-MS and ESI-MSn. Endoxylanase digested KOH-sol AXs are also characterized by nuclear magnetic resonance (NMR) that also provides information on the anomeric configuration. These techniques can be applied to other classes of polysaccharides using the appropriate endo-hydrolases.

Sequencing of Plant Wall Heteroxylans Using Enzymic, Chemical Methylation and Physical Mass Spectrometry, Nuclear Magnetic Resonance Techniques

This protocol describes the specific techniques used for the structural characterization of reducing end (RE) and internal region glycosyl sequence(s) of heteroxylans by tagging the RE with 2 aminobenzamide prior to enzymatic (endoxylanase) hydrolysis and then analysis of the resultant oligosaccharides using mass spectrometry (MS) and nuclear magnetic resonance (NMR).

使用酶法，化学（甲基化）和物理（质谱，核磁共振）技术，植物墙Heteroxylans测序

This protocol describes the specific techniques used for the characterization of reducing end (RE) and internal region glycosyl sequence(s) of ...

In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging

A method is demonstrated to monitor macroscopic translational diffusion using electron paramagnetic resonance (EPR) imaging. A host-guest system with nitroxide spin probe 3-(2-Iodoacetamido)-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (IPSL) as a guest inside the periodic mesoporous organosilica (PMO) aerogel UKON1-GEL as a host and ethanol as a solvent is used as an example to describe the protocol. Data is shown from a previous publication, where the protocol has been applied to both IPSL and Tris(8-carboxy-2,2,6,6-perdeutero-tetramethyl-benzo[1,2-d:4,5-d&#8242;]bis(1,3)dithiole) methyl (Trityl) as guest molecules and UKON1-GEL and SILICA-GEL as host systems. 
A method is shown to prepare aerogel samples that cannot be synthesized directly in the sample tube for measurement due to a size change during synthesis. The aerogel is attached to sample tubes using heat shrink tubing and a pressure cooker to reach the necessary temperature without evaporating the solvent in the process. The method does not assume a clearly defined initial distribution of guest molecules at the start of the measurement. Instead, it requires a reservoir on top of the aerogel and experimentally determines the influx rate during data analysis.
The diffusion is monitored continually over a period of 20 hr by recording the 1d spin density profile within the sample. The spectrometer settings for the imaging experiment are described quantitatively. Data analysis software is provided to take the resonator sensitivity profile into account and to numerically solve the diffusion equation. The software determines the macroscopic translational diffusion coefficient by least square minimization of the difference between the experiment and the numerical solution of the diffusion equation.

In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging

A protocol for the in situ monitoring of the diffusion of guest molecules in porous media using electron paramagnetic resonance (EPR) imaging is presented.

在多孔介质中使用电子顺磁共振成像客体分子扩散的原位监测

A method is demonstrated to monitor macroscopic translational diffusion using electron paramagnetic resonance (EPR) imaging. A host-guest system with ...

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) and their roles in environmental microbiology. This study outlines a method to cultivate biofilm attachment to the System for Analysis at the Liquid Vacuum Interface (SALVI) and achieve in situ chemical mapping of a living biofilm by time-of-flight secondary ion mass spectrometry (ToF-SIMS). This is done through the culturing of bacteria both outside and within the SALVI channel with our specialized setup, as well as through optical imaging techniques to detect the biofilm presence and thickness before ToF-SIMS analysis. Our results show the characteristic peaks of the Shewanella biofilm in its natural hydrated state, highlighting upon its localized water cluster environment, as well as EPS fragments, which are drastically different from the same biofilm's dehydrated state. These results demonstrate the breakthrough capability of SALVI that allows for in situ biofilm imaging with a vacuum-based chemical imaging instrument.

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

This article presents a method for growing a biofilm for in situ time-of-flight secondary ion mass spectrometry for chemical mapping in its hydrated state, enabled by a microfluidic reactor, System for Analysis at the liquid Vacuum Interface. The Shewanella oneidensis MR-1 with green fluorescence protein was used as a model.

原位萨尔和 TOF-SIMS希瓦氏菌 oneidensis MR1 生物膜的表征

Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) ...

A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites

The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and related diseases, but their precise measurement is still a challenge. Many protocols have been described for neurotransmitter measurement by a variety of instruments, including high-pressure liquid chromatography (HPLC). However, there are shortcomings, such as complicated operation or hard-to-detect multiple targets, which cannot be avoided, and presently, the dominant analysis technique is still HPLC coupled with sensitive electrochemical or fluorimetric detection, due to its high sensitivity and good selectivity. Here, a detailed protocol is described for the pretreatment and detection of catecholamines with high pressure liquid chromatography with electrochemical detection (HPLC-ECD) in real urine samples of infants, using electrospun composite nanofibers composed of polymeric crown ether with polystyrene as adsorbent, also known as the packed-fiber solid phase extraction (PFSPE) method. We show how urine samples can be easily precleaned by a nanofiber-packed solid phase column, and how the analytes in the sample can be rapidly enriched, desorbed, and detected on an ECD system. PFSPE greatly simplifies the pretreatment procedures for biological samples, allowing for decreased time, expense, and reduction of the loss of targets. 
Overall, this work illustrates a simple and convenient protocol for solid-phase extraction coupled to an HPLC-ECD system for simultaneous determination of three monoamine neurotransmitters (norepinephrine (NE), epinephrine (E), dopamine (DA)) and two of their metabolites (3-methoxy-4-hydroxyphenylglycol (MHPG) and 3,4-dihydroxy-phenylacetic acid (DOPAC)) in infants' urine. The established protocol was applied to assess the differences of urinary catecholamines and their metabolites between high-risk infants with perinatal brain damage and healthy controls. Comparative analysis revealed a significant difference in urinary MHPG between the two groups, indicating that the catecholamine metabolites may be an important candidate marker for early diagnosis of cases at risk for brain damage in infants.

We present a convenient solid-phase extraction coupled to high-pressure liquid chromatography (HPLC) with electrochemical detection (ECD) for simultaneous determination of three monoamine neurotransmitters and two of their metabolites in infants' urine. We also identify the metabolite MHPG as a potential biomarker for the early diagnosis of brain damage for infants.

用高压液相色谱法提取和分析儿茶酚胺神经递质及其代谢物的简便方法

The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and ...

Using Graphene Liquid Cell Transmission Electron Microscopy to Study in Situ Nanocrystal Etching

Graphene liquid cell electron microscopy provides the ability to observe nanoscale chemical transformations and dynamics as the reactions are occurring in liquid environments. This manuscript describes the process for making graphene liquid cells through the example of graphene liquid cell transmission electron microscopy (TEM) experiments of gold nanocrystal etching. The protocol for making graphene liquid cells involves coating gold, holey-carbon TEM grids with chemical vapor deposition graphene and then using those graphene-coated grids to encapsulate liquid between two graphene surfaces. These pockets of liquid, with the nanomaterial of interest, are imaged in the electron microscope to see the dynamics of the nanoscale process, in this case the oxidative etching of gold nanorods. By controlling the electron beam dose rate, which modulates the etching species in the liquid cell, the underlying mechanisms of how atoms are removed from nanocrystals to form different facets and shapes can be better understood. Graphene liquid cell TEM has the advantages of high spatial resolution, compatibility with traditional TEM holders, and low start-up costs for research groups. Current limitations include delicate sample preparation, lack of flow capability, and reliance on electron beam-generated radiolysis products to induce reactions. With further development and control, graphene liquid cell may become a ubiquitous technique in nanomaterials and biology, and is already being used to study mechanisms governing growth, etching, and self-assembly processes of nanomaterials in liquid on the single particle level.

Using Graphene Liquid Cell Transmission Electron Microscopy to Study in Situ Nanocrystal Etching

Graphene liquid cell electron microscopy can be used to observe nanocrystal dynamics in a liquid environment with greater spatial resolution than other liquid cell electron microscopy techniques. Etching premade nanocrystals and following their shape using graphene liquid cell Transmission Electron Microscopy can yield important mechanistic information about nanoparticle transformations.

用石墨烯液细胞透射电镜研究原位纳米晶蚀刻

Graphene liquid cell electron microscopy provides the ability to observe nanoscale chemical transformations and dynamics as the reactions are occurring in ...