作者承认从美国国家科学基金会（NSF）的财政支持给予EEC-0540832，题为"中红外技术用于健康和环境（MIRTHE）"

工具1。准备<ol><li>打开外部电源向氨光学传感器平台，激光二极管控制器，定制的电子控制单元（CEU），呼吸采样器，空气泵，和笔记本电脑。 </li><li>检查氨气传感器的两个排气和冷却风扇是否工作。注意:一个是位于传感器的后面，第二个是传感器，它是方便内发现的。 </li><li>确保声波检测模块和针阀温度是在38.0℃下通过检查数字显示位于氨传感器盒子的侧面上。等待大约35分钟从传感器提供电源的稳定温度的时间。 </li><li>通过点击一个图标名称"ChangeT"呼吸采样器的桌面上找到设置入口管路和喉舌温度为55℃。温度就可以通过单击向上或向下箭头依次点击"欠电位沉积而改变吃温度"。点击"退出"返回到桌面。允许该系统中至少5分钟至温度稳定。保持采样器和管路的在55℃的温度下最小化氨的表面损失。 </li><li>于控制氨气传感器的笔记本电脑打开软件。该程序可以命名桌面上的"NH 3呼吸传感器程序"文件夹中进行访问。在此文件夹中，用户必须选择图标"主LabVIEW软件"。此文件夹包含多个应用程序，但用户必须选择"Mainsequence.vi"访问所需的接口。在屏幕的左上角选择"运行"。注:这将开始行锁定校准序列。该QEPAS监视器的激光运行在一个最佳电流，这是一个自动化的线锁紧过程中选定的。这个过程大约需要25分钟。 </li><li>创建采样器一个新的会话，使得EACH主题会话都有被保存到一个附加的闪存驱动器它自己的文件。注:这是打开程序"呼吸取样"的取样器的桌面上找到执行。有空间，适当识别会话。在会话期间生成的所有数据都将根据该标识符被保存在闪存驱动器。实验的时间是通常用来作为文件名的一部分。进样口和喉舌温度必须进入呼吸取样程序之前进行调整。 </li><li>插入一个新的一次性吹嘴进入进气管。戴上一次性手套，以避免污染喉舌与手指氨。 </li></ol> 2，呼气样品采集注:有关机构审查委员会（伦理委员会）必须批准，涉及人类受试者的任何研究。有许多因素会极大地影响呼吸氨。这些因素可以通过直接修改一个呼吸测量氨ffecting全身氨的水平或影响呼吸代谢的旅程从肺输送到仪器。 <ol><li>确保受试者到达实验室在空腹状态下，有没有消费的食品抵达后约12小时，他们已经行使上午前测试忍住了。 </li><li>确保没有物质已被引入口至少1小时前的数​​据收集。确保受试者刷比试验前1小时大于他们的牙齿。 </li><li>座位在氨气传感器的前面的主题。指示须持有进水管，并确保他们不碰的喉舌，以避免氨气污染。 </li><li>点击采样界面上的"开始"。已受试者呼气对着话筒，只要他们能，或直到操作员认为该样品是足够的。注意:这是一个充满呼气持续至少10秒。口压力的测量是实时地作为替代为流率。颜色编码的压力表帮助主题产生和保持10厘米的水所需的呼气压力，它表示为50毫升/秒呼气流速。该流量设定，因为它已经通过了ATS / ERS的协议来确定铁NO。本呼气流速是可以实现的儿童和成人。同样该相差小于10％，3重现的呼气应获得。 </li><li>时呼气样品完成后，单击"停止"采样器接口。 </li></ol> 3，呼气样本测试<ol><li>一旦呼气样本进行了分析，实验室技术人员操作监视器，那么有分析认为呼吸配置文件的任何部分的能力。呼吸是感兴趣的部分是第三阶段的段。这个特点是在二氧化碳的浓度的"平台"，并在中间被发现的BRE的后期ATH。 </li><li>通过拖动采样器界面上的垂直线呼吸的压力降前夕，开始时的二氧化碳高原和停止选择样本的III期部分。参见图1澄清。 </li><li>通过单击取样触摸屏界面的"商店"将数据保存到闪存驱动器。 </li><li>一旦呼吸数据已存储，用户可以选择"开始"来启动一个新的呼气样本。 </li></ol> 4，龙虎斗漱口水和pH值的影响在呼气氨<ol><li>样品3次呼吸，以建立基线氨水平。确保呼吸采取至少5分钟彼此分开。 </li><li>用30毫升一份水60秒彻底漱口。 </li><li>在60秒内冲洗（第2节）的收集呼气样本。收集呼气样本在接下来的一个小时的过程中，观察氨随时间的变化。注:山姆普莱斯可以作为经常作为每一分钟，但较长的时间间隔通常使用。 </li><li>用30毫升一份的碱性溶液（在水中的碳酸氢钠），彻底漱口60秒，重复4.2.1。 </li><li>用30毫升一份的60秒酸性溶液彻底冲洗口腔，并重复4.2.1。 </li></ol> 5，龙虎斗的进口和运输管温度的影响对呼吸氨<ol><li>样品3次呼吸超过15分钟，与入口温度的过程中设置为低于体温约30℃。 </li><li>使用呼吸采样器的触摸屏界面上的桌面图标增加进口和运输管道的温度到55°C分别。允许该系统中至少5分钟，以达到稳定状态。 </li><li>样品3次呼吸，5分钟分割成加热的入口。 </li></ol>

<ol><li>Adeva, M. M., Souto, G., Blanco, N., Donapetry, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Ammonium+metabolism+in+humans%5BTitle%5D)+AND+%22Metabolism%3A+clinical+and+experimental%22%5BJournal%5D)">Ammonium metabolism in humans.</a> Metabolism: clinical and experimental. 61 (11), 1495-1511 (2012).</li>
<li>Auron, A., Brophy, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Hyperammonemia+in+review%3A+pathophysiology%2C+diagnosis%2C+and+treatment%5BTitle%5D)+AND+%22Pediatric+nephrology%22%5BJournal%5D)">Hyperammonemia in review: pathophysiology, diagnosis, and treatment.</a> Pediatric nephrology. 27 (2), 207-222 (2012).</li>
<li>Blanco Vela, C. I., Bosques Padilla, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Determination+of+ammonia+concentrations+in+cirrhosis+patients-still+confusing+after+all+these+years%5BTitle%5D)+AND+%22Annals+of+hepatology%22%5BJournal%5D)">Determination of ammonia concentrations in cirrhosis patients-still confusing after all these years.</a> Annals of hepatology. 10 Suppl 2, (2011).</li>
<li>Mpabanzi, L., Ol de Damink, S. W. M., van de Poll, M. C. G., Soeters, P. B., Jalan, R., Dejong, C. H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((To+pee+or+not+to+pee%3A+ammonia+hypothesis+of+hepatic+encephalopathy+revisited%5BTitle%5D)+AND+%22European+journal+of+gastroenterology+%26+hepatology%22%5BJournal%5D)">To pee or not to pee: ammonia hypothesis of hepatic encephalopathy revisited.</a> European journal of gastroenterology & hepatology. 23 (6), 449-454 (2011).</li>
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<li>Huizenga, J. R., Tangerman, A., Gips, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Determination+of+ammonia+in+biological+fluids%5BTitle%5D)+AND+%22Annals+of+clinical+biochemistry%22%5BJournal%5D)">Determination of ammonia in biological fluids.</a> Annals of clinical biochemistry. 31 (Pt 6), 529-543 (1994).</li>
<li>Lewicki, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Real+time+ammonia+detection+in+exhaled+human+breath+with+a+quantum+cascade+laser+based+sensor%5BTitle%5D)+AND+%222009+Conference+on+Lasers+and+ElectroOptics+and+2009+Conference+on+Quantum+electronics+and+Laser+Science+Conference%22%5BJournal%5D)">Real time ammonia detection in exhaled human breath with a quantum cascade laser based sensor.</a> 2009 Conference on Lasers and ElectroOptics and 2009 Conference on Quantum electronics and Laser Science Conference. 1, (2009).</li>
<li><a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((American+Thoracic+Society.+European+Respiratory+Society.+Recommendations+for+Standardized+Procedures+for+the+Online+and+Offline+Measurement+of+Exhaled+Lower+Respiratory+Nitric+Oxide+and+Nasal+Nitric+Oxide%5BTitle%5D)+AND+%22American+journal+of+respiratory+and+critical+care+medicine%22%5BJournal%5D)">American Thoracic Society. European Respiratory Society. Recommendations for Standardized Procedures for the Online and Offline Measurement of Exhaled Lower Respiratory Nitric Oxide and Nasal Nitric Oxide.</a> American journal of respiratory and critical care medicine. 171 (8), 912-930 (2005).</li>
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</ol>

Dr. Risby serves as a consultant for Loccioni Humancare the manufacturer of the breath sampler.

能够检测到微量的代谢产物进行实时一种非侵入性程序的好处是显而易见的。然而，呼吸研究领域一直在努力实现这一潜力。呼吸测量是一个动态的过程中容易受到很多干扰因素。我们的方法具有重要的优势:即，水稻QEPAS基氨显示器耦合到所述呼吸采样器的灵敏度和速度，使我们能够评估和确定有密切关系的精确测量呼气采集的因素。这种方法是非常可靠的:例如，一些初步的实验后，每收集最近的实验中几乎500个人呼吸数据点是与预期结果9号一致。 直到影响呼出气体氨的各种因素得到更好的理解，但重要的是提供彻底和均匀的指示受试者在到达之前。目前，我们一般要求受试者午夜早上集合后快，刷不到1小时前呈现较大的牙齿，并避免运动，吸烟，或填充的汽车与石油燃料。虽然我们已经评估了各种食物养生之道的前一天晚上的数据收集（ 如高纤维诉低纤维），我们还没有建立，饮食令人信服地影响基准数据测试的早晨。早上集合也可以减少明显的日变化特征，这似乎发生原因不明13的影响。 可能还有其他同样有效或更好的方法呼出一口气氨集合。这是可能的，例如，在设定的时间点之前的呼吸收集的标准冲洗可能导致口腔粘膜氨的有用的测量可能还反映全身水平。另一个路径可能是放弃了口腔和鼻腔测量氨或两者10,14。后一种方法可以不必FOr处的接口采样。无论如何，任何方法需要仔细考虑各种相关与这个动荡的代谢产物，包括湿度，温度，pH值，流量，以及口咽部生物技术因素。 当然，假设和信念的测量方法对数据分析的关键轴承。我们认为，压力和二氧化碳是质量控制的关键方面。然而，这不是一定的，例如，无论是作为测定氨应报告，或二氧化碳调节，以单位为ppb的或皮摩尔。随着越来越多的经验和信心都获得了错误的各种技术资源，在复杂的考虑现任的数据分析来为更大的重点和将推动更好地理解这个非常具有挑战性的生物。 （ 图2:随机和非随机误差测量真实的生物学变异而非生物附带现象或 B异常呼吸。和口腔/鼻腔因素或C和 D。设备性能。） <img alt="图2" fo:content-width="5in" src="/files/ftp_upload/51658/51658fig2highres.jpg" width="500" /> 图病人2。图一口气接口氨显示器。 a）病人进行测试，也是一口气收集过程中最不可预测的部分。患者的饮食，运动，吸烟习惯，可以对数据收集大的影响。 二）呼吸呼气是可变的，从人到人，所以一个方法，以规范的呼吸是很重要的。提供视觉提示，以提供空气从肺部理想流量能够很好地保持呼气均匀的。C）呼吸接口装置被紧密地在呼气一致性相关的B是在比较对象的重要因素。呼气采样器集成rface使得用户可以看到实时的各种呼吸试样参数D）氨显示器可以表现出来的不同的技术。石英增强的光声光谱有认为是理想的呼吸分析许多固有优势。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/51658/51658fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 重要的限制本发明的方法必须被确认。而采样器是相对便宜和轻便，氨显示器，使用目前的配置，是两者都不是。因此，受试者需要来我们的专用呼吸的研究空间，因为我们不能轻易地我们的装备移动到诊所。这个因素，连同受试者的呼气吐气一个长吸一口气的要求，哪些题目可以研究（ 即患病肝硬化患者，一个关键的目标人群，影响往往PRACtically除外）。此外，因为我们只有一个显示器，我们在可切实研究在给定的协议对象的数量限制。反过来，这会影响样品的尺寸和功率。 如上所述，一氧化氮的收集标准化是由美国胸科协会和欧洲呼吸学会的共同努力。目前并呼吸氨气没有对等的协议，尽管多组正在为呼吸测量氨的进步做出重要贡献。作为一般的一丝气息代谢物的测量和氨，特别是文学的不断发展15肯定会有很多修改和改进的到来。显示器的体积更小，更轻便，更便宜是成功的多中心临床试验中是至关重要的。

氨是蛋白质代谢1无处不在的副产品。因此，氨测量可以帮助医生评估各种疾病和健康状态2。然而，氨是很难精确测量，通过血液或呼气，因为它是非常活泼。虽然常用，血液化验有许多缺点，包括约3精度基本问题。但随着血液化验的主要问题是，他们永远只能收集幕的现实。这是重要的，因为氨的生理，就像血糖和其他许多代谢过程，是流动的和不断变化4。相比之下，呼吸分析是完全非侵入性，快速，从而容易使重复测量。因此，呼气氨测量是有吸引力的，因为它可能会解决一个严重的未满足的需要以独特的方式。 呼气收集，然而，提出了独特的顾虑。而放血天生携带JEO错误的几种不可预知的方式pardy（ 例如 ，止血带的时间，汗水污染，血细胞溶血，延误实验室测量等5），呼吸测量研究者必须与不同组新的挑战:变异呼吸，污染与口腔黏膜或细菌氨，周围空气和装置的湿度和温度的影响，等6。事实上，这是不可低估的任务中使用的实验程序，以发现未知生物实验设备连接到人类。在由于这些障碍的一部分，呼气氨尚未达到其潜力。 在此，我们提出我们的呼吸氨测量协议进行快速，准确的结果。我们的协议有实力在三个方面:显示器，接口采样，并注意人类活动的影响。该显示器是由赖斯大学的同事建立如前面所述7。 MEA的基础几种常用的是石英增强的光声光谱法（QEPAS）技术，它采用一个压电石英音叉作为声换能器。当声波通过调制激光辐射的目标痕量气体物质的吸收发生产生光声效应。使用声电池，它是声学谐振的调制频率被检测出的微量的气体。吸收波长为氨被选中，是免费的从呼吸中干扰物质的光谱干扰。人类呼出气体测量的目的，显示器的主要功能包括广泛的测量范围（从50〜十亿分之，ppb到至少5000 PPB）和速度（1秒测量的）。显示器的速度使得时间分辨率在整个呼吸周期。 该显示器被连接到专门设计的呼吸采样器。该采样器包括一个压力传感器和二氧化碳监测仪的。它显示和归档实时测量口压力和二氧化碳以及由传感器测定的氨浓度。该取样器，因此，使技术人员来评估呼吸努力的质量为呼吸是收集。这使我们能够超越，分析呼吸一氧化氮（NO铁），提出由美国胸科协会/欧洲呼吸学会的特别工作组（ATS / ERS）8的建议。对于所有的呼吸气体取样，一次性单向管式阀​​被用在呼气采样口口。 因为采样器提供显示器和质量控制的速度，我们可以仔细评估人类影响9。大多数受试者，例如，最初强力呼吸时指示呼吸。其他重要的影响，如口服pH和口腔冲洗液，温度的取样器，显示器和所有相关联的管道，和呼吸模式，随后的研究，并且是依据FOř下面的说明实验。 最后，也许是最显著，但必须强调的是多个经验丰富的组采用完全不同的传感器和测量程序测量呼气氨。这可能有重要的优势和有效性。一个完整的比较超出了目前的工作10,11,12的范围。

<table><tbody><tr><td>Rice Ammonia Monitor System</td><td>N/A</td><td>N/A</td><td>Not available for commercial purchase</td></tr><tr><td>Loccioni Breath Sampler</td><td>Loccioni Humancare</td><td>N/A</td><td>Single breath version</td></tr><tr><td>Disposable Mouth Piece</td><td>WestPrime Healthcare</td><td>G011-200</td><td>Manufacturer is AlcoQuant</td></tr><tr><td>Laptop</td><td>Lenovo</td><td>N/A</td><td>Old model no longer sold by manufacturer</td></tr><tr><td>Acid Rinse</td><td>N/A</td><td>N/A</td><td>Household acidic drink (coffee, soft drink, citrus juices, etc)</td></tr><tr><td>Base Rinse</td><td>N/A</td><td>N/A</td><td>Water mixed with a nonexact amount of sodium bicarbonate (Arm &amp;amp; Hammer Baking Soda)</td></tr><tr><td>Neutral Rinse</td><td>N/A</td><td>N/A</td><td>Water</td></tr></tbody></table>

fast and accurate exhaled breath ammonia measurement

This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that uses a quantum cascade based laser. The monitor is coupled to a sampler that measures mouth pressure and carbon dioxide. The system is temperature controlled and specifically designed to address the reactivity of this compound. The sampler provides immediate feedback to the subject and the technician on the quality of the breath effort. Together with the quick response time of the monitor, this system is capable of accurately measuring exhaled breath ammonia representative of deep lung systemic levels. 
Because the system is easy to use and produces real time results, it has enabled experiments to identify factors that influence measurements. For example, mouth rinse and oral pH reproducibly and significantly affect results and therefore must be controlled. Temperature and mode of breathing are other examples. As our understanding of these factors evolves, error is reduced, and clinical studies become more meaningful. This system is very reliable and individual measurements are inexpensive. 
The sampler is relatively inexpensive and quite portable, but the monitor is neither. This limits options for some clinical studies and provides rational for future innovations.

主题可望产生广泛的基线呼吸氨的水平。健康的个体可以开始于100-1,000 ppb的呼气氨测定的日子。漂洗口与任何流体立即改变检测呼气氨的量。中性和酸性流体通常由多于一半切观察氨的量。这些水平然后返回到基线作为漂洗的效果逐渐消失。水的影响似乎在15分钟内消散，而酸可以保持呼吸检测到氨最少超过2小时。一个基本的清洗，如碳酸氢钠，回到基线在20分钟内之前将增加一倍或两倍检测呼气氨的量。值得注意的是，过氧化氢似乎不影响呼出气氨多于其他漂洗;因此，它似乎并不认为口腔细菌显著呼吸测量氨的贡献。 正如一波夫，耦合到所述氨传感器的采样器提供连续的数据，技术人员可以使用它来评估呼吸样本的质量。口压力和二氧化碳是用来验证一个呼吸试样呼气的两个特征。口压力作为替代，以空气流从肺进入取样器。技术人员必须确保被摄对象提供足够的流动肺泡的空气，其中包含利息的代谢产物，在显示器中。技术人员应该期望的水9〜10.5厘米，口正常压力范围。呼气应该是相当稳定超过10-20秒，这体现在口压力的标准偏差的过程。的呼吸质量的标准偏差应小于1厘米的水。 二氧化碳的测量也是重要的，因为它使呼气过程中仔细评估。在第一阶段，呼气开始和呼出的气体的组成是由预显性解剖死空间的空气（〜21％的氧，0.03％的二氧化碳，78％氮和0.5％水）， 即 ，，这是在以前的呼吸周期的吸气阶段吸入的空气中。在第二阶段，肺泡气体通入解剖死空间和混合残余死空间的空气，其结果是二氧化碳的浓度增加迅速。二氧化碳呼出气浓度继续上升，虽然速度比较慢，三期和呼气峰值（呼气末浓度）相当于二氧化碳的静脉血浓度时。阶段III期间，这个逐渐上升的二氧化碳浓度是由于与死空间的空气的剩余部分肺泡气体的混合，是由于缓慢的肺泡囊的排空。呼吸在III期结束时，组合物是约13％氧气，5％二氧化碳，78％氮和4％的水。在BRE的第三阶段部分中的二氧化碳水平ATH的范围可以从30至40毫米汞柱。第三阶段对应于这些的CO 2水平的高原（ 图1A-D）。 <img alt="图1" fo:content-width="5in" src="/files/ftp_upload/51658/51658fig1highres.jpg" width="500" /> 图1的呼吸样本，集成的呼吸数据的第三阶段的部分，用于在各种条件。 1a）的一个典型的呼气样本，集成了一口气数据的第三阶段部分。绿色和红色的垂直线设置的跨度，其中线路是待分析。呼气的第一部分将被忽略。1b）中的酸性漂洗有对呼吸氨的影响。的NH 3与NH 4 +的转换急剧降低检测的氨的量。下降气流导致肺泡氨在如1c中看到的采样呼吸的降低。减少的流量确实ÑOT让尽可能多的肺泡的空气进行采样。1D）呼气样本，集成阶段I，II和III。 I和II中的分析列入阶段降低氨和二氧化碳相当。这是系统性氨的准确反映。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/51658/51658fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 大多数受试者都能够产生可以接受的气息在他们的第一次尝试。然而，有些科目需要呼吸的重演。此外，由于压力和二氧化碳被记录时，这些也可以在数据分析中考虑。

Watch this Scientific Journal Video about Fast and Accurate Exhaled Breath Ammonia Measurement at JoVE.com

Fast and Accurate Exhaled Breath Ammonia Measurement

Ammonia is an important physiologic metabolite relevant to various disease and wellness states. It is also a difficult molecule to measure in breath, which demands particular precautions be taken to obtain accurate results. Not all factors influencing ammonia are known, but progress can be difficult without accounting for these factors.

快速，准确的呼出气测量氨

This exhaled breath ammonia method uses a fast and highly sensitive spectroscopic method known as quartz enhanced photoacoustic spectroscopy (QEPAS) that ...

fast-and-accurate-exhaled-breath-ammonia-measurement

Nanyang Technological University

Research

JoVE Journal

Medicine

13.4K 次观看.  St. Luke's University Hospital. Ammonia is an important physiologic metabolite relevant to various disease and wellness states. It is also a difficult molecule to measure in breath, which demands particular precautions be taken to obtain accurate results. Not all factors influencing ammonia are known, but progress can be difficult without accounting for these factors.

视频: Fast and Accurate Exhaled Breath Ammonia Measurement

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high surface area microporous materials, such as metal-organic frameworks (MOFs), unique challenges present themselves for PECVD treatments. Herein the protocol for development of a MOF that was previously unstable to humid conditions is presented. The protocol describes the synthesis of Cu-BTC (also known as HKUST-1), the treatment of Cu-BTC with PECVD of perfluoroalkanes, the aging of materials under humid conditions, and the subsequent ammonia microbreakthrough experiments on milligram quantities of microporous materials. Cu-BTC has an extremely high surface area (~1,800 m2/g) when compared to most materials or surfaces that have been previously treated by PECVD methods. Parameters such as chamber pressure and treatment time are extremely important to ensure the perfluoroalkane plasma penetrates to and reacts with the inner MOF surfaces. Furthermore, the protocol for ammonia microbreakthrough experiments set forth here can be utilized for a variety of test gases and microporous materials.

Herein the procedures for plasma enhanced chemical vapor deposition of perfluoroalkanes on microporous materials such as metal-organic frameworks to enhance their stability and hydrophobicity are described. Furthermore, breakthrough testing of milligram quantities of samples is described in detail.

增强型氟烷烃的化学气相沉积等离子通过疏水金属 - 有机骨架的制备氨的去除

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high ...

科研

化学

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% fine dust formation within the EU15. But NH3 emissions also mean a considerable loss of nutrients. Many studies on NH3 emission from organic and mineral fertilizer application have been performed in recent decades. Nevertheless, research related to NH3 emissions after application fertilizers is still limited in particular with respect to relationships to emissions, fertilizer type, site conditions and crop growth. Due to the variable response of crops to treatments, effects can only be validated in experimental designs including field replication for statistical testing. The dominating ammonia loss methods yielding quantitative emissions require large field areas, expensive equipment or current supply, which restricts their application in replicated field trials. This protocol describes a new methodology for the measurement of NH3 emissions on many plots linking a simple semi-quantitative measuring method used in all plots, with a quantitative method by simultaneous measurements using both methods on selected plots. As a semi-quantitative measurement method passive samplers are used. The second method is a dynamic chamber method (Dynamic Tube Method) to obtain a transfer quotient, which converts the semi-quantitative losses of the passive sampler to quantitative losses (kg nitrogen ha-1). The principle underlying this approach is that passive samplers placed in a homogeneous experimental field have the same NH3 absorption behavior under identical environmental conditions. Therefore, a transfer co-efficient obtained from single passive samplers can be used to scale the values of all passive samplers used in the same field trial. The method proved valid under a wide range of experimental conditions and is recommended to be used under conditions with bare soil or small canopies (&#60;0.3 m). Results obtained from experiments with taller plants should be treated more carefully.

Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers

Ammonia emissions are a major threat to the environment by eutrophication, soil acidification and fine particle formation and stem mainly from agricultural sources. This method allows ammonia loss measurements in replicated field trials enabling statistical analysis of emissions and of relationships between crop development and emissions.

校准被动采样 - NH多情节场测量<sub&gt; 3</sub&gt;与动态管法和被动采样的组合排放

Agricultural ammonia (NH3) emissions (90% of total EU emissions) are responsible for about 45% airborne eutrophication, 31% soil acidification and 12% ...

环境科学

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Nitrogen oxides (NOx = NO + NO2) are a family of atmospheric trace gases that have great impact on the environment. NOx concentrations directly influence the oxidizing capacity of the atmosphere through interactions with ozone and hydroxyl radicals. The main sink of NOx is the formation and deposition of nitric acid, a component of acid rain and a bioavailable nutrient. NOx is emitted from a mixture of natural and anthropogenic sources, which vary in space and time. The collocation of multiple sources and the short lifetime of NOx make it challenging to quantitatively constrain the influence of different emission sources and their impacts on the environment. Nitrogen isotopes of NOx have been suggested to vary amongst different sources, representing a potentially powerful tool to understand the sources and transport of NOx. However, previous methods of collecting atmospheric NOx integrate over long (week to month) time spans and are not validated for the efficient collection of NOx in relevant, diverse field conditions. We report on a new, highly efficient field-based system that collects atmospheric NOx for isotope analysis at a time resolution between 30 min and 2 hr. This method collects gaseous NOx in solution as nitrate with 100% efficiency under a variety of conditions. Protocols are presented for collecting air in urban settings under both stationary and mobile conditions. We detail the advantages and limitations of the method and demonstrate its application in the field. Data from several deployments are shown to 1) evaluate field-based collection efficiency by comparisons with in situ NOx concentration measurements, 2) test the stability of stored solutions before processing, 3) quantify in situ reproducibility in a variety of urban settings, and 4) demonstrate the range of N isotopes of NOx detected in ambient urban air and on heavily traveled roadways.

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Previous work suggests that the nitrogen isotopic composition of atmospheric nitrogen oxides might distinguish the influence of different sources in the environment. We report on an automated, mobile, field-based method for the high collection efficiency of atmospheric NOx for N isotopic analysis at an hourly time resolution.

自动化，高清晰度移动采集系统对NO的氮同位素分析<sub系列&gt; X</sub

Nitrogen oxides (NOx = NO + NO2) are a family of atmospheric trace gases that have great impact on the environment. NOx concentrations directly influence ...

Assessment of Methane and Nitrous Oxide Fluxes from Paddy Field by Means of Static Closed Chambers Maintaining Plants Within Headspace

This protocol describes the measurement of greenhouse gas (GHG) emissions from paddy soils using the static closed chamber technique. This method is based on the diffusion theory. A known volume of air overlaying a defined soil area is enclosed within a parallelepiped cover (named &#34;chamber&#34;), for a defined period of time. During this enclosure period, gases (methane (CH4) and nitrous oxide (N2O)) move from soil pore air near their microbial source (i.e., methanogens, nitrifiers, denitrifiers) to the chamber headspace, following a natural concentration gradient. Fluxes are then estimated from chamber headspace concentration variations sampled at regular intervals throughout the enclosure and then analyzed with gas chromatography. Among the techniques available for GHG measurement, the static closed chamber method is suitable for plot experiments, as it does not require large homogenously treated soil areas. Furthermore, it is manageable with limited resources and can identify relationships among ecosystem properties, processes, and fluxes, especially when combined with GHG driving force measurements. Nevertheless, with respect to the micrometeorological method, it causes a minimal but still unavoidable soil disturbance, and allows a minor temporal resolution. Several phases are key to the method implementation: i) chamber design and deployment, ii) sample handling and analyses, and iii) flux estimation. Technique implementation success in paddy fields demands adjustments for field flooding during much of the cropping cycle, and for rice plant maintenance within the chamber headspace during measurements. Therefore, the additional elements to be considered with respect to the usual application of non-flooded agricultural soils consist of devices for: i) avoiding any unintended water disturbance that could overestimate fluxes, and ii) including rice plants within the chamber headspace to fully consider gases emitted through aerenchyma transportation.

The overall goal of this protocol is to measure greenhouse gas emissions from paddy fields using the static closed chamber technique. The measurement system needs specific adjustments due to the presence of both a permanent water layer in the field and of the plants within the chamber headspace.

用静止封闭室维持顶空装置对稻田甲烷和一氧化二氮通量的评价

This protocol describes the measurement of greenhouse gas (GHG) emissions from paddy soils using the static closed chamber technique. This method is based ...

Design and Use of a Full Flow Sampling System (FFS) for the Quantification of Methane Emissions

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas industry faces continued scrutiny for methane emissions from across the supply chain, due to methane&#39;s relatively high global warming potential (25-84x that of carbon dioxide, according to the Energy Information Administration). Currently, a variety of techniques of varied uncertainties exists to measure or estimate methane emissions from components or facilities. Currently, only one commercial system is available for quantification of component level emissions and recent reports have highlighted its weaknesses.
In order to improve accuracy and increase measurement flexibility, we have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases based on transportation emissions measurement principles. The FFS is a modular system that consists of an explosive-proof blower(s), mass airflow sensor(s) (MAF), thermocouple, sample probe, constant volume sampling pump, laser based greenhouse gas sensor, data acquisition device, and analysis software. Dependent upon the blower and hose configuration employed, the current FFS is able to achieve a flow rate ranging from 40 to 1,500 standard cubic feet per minute (SCFM). Utilization of laser-based sensors mitigates interference from higher hydrocarbons (C2+). Co-measurement of water vapor allows for humidity correction. The system is portable, with multiple configurations for a variety of applications ranging from being carried by a person to being mounted in a hand drawn cart, on-road vehicle bed, or from the bed of utility terrain vehicles (UTVs). The FFS is able to quantify methane emission rates with a relative uncertainty of &#177; 4.4%. The FFS has proven, real world operation for the quantification of methane emissions occurring in conventional and remote facilities.

Design and Use of a Full Flow Sampling System FFS for the Quantification of Methane Emissions

We have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases from across the natural gas supply chain.

设计和全流采样系统（FFS）的使用甲烷排放的量化

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas ...

工程学

Real-time Breath Analysis by Using Secondary Nanoelectrospray Ionization Coupled to High Resolution Mass Spectrometry

Exhaled volatile organic compounds (VOCs) have aroused considerable interest, since they can serve as biomarkers for disease diagnosis and environmental exposure in a non-invasive manner. In this work, we present a protocol to characterize the exhaled VOCs in real time by using secondary nanoelectrospray ionization coupled to high resolution mass spectrometry (Sec-nanoESI-HRMS). The homemade Sec-nanoESI source was readily set up based on a commercial nanoESI source. Hundreds of peaks were observed in the background-subtracted mass spectra of exhaled breath, and the mass accuracy values are -4.0-13.5 ppm and -20.3-1.3 ppm in the positive and negative ion detection modes, respectively. The peaks were assigned with accurate elemental composition according to the accurate mass and isotopic pattern. Less than 30 s is used for one exhalation measurement, and it takes approximately 7 min for six replicated measurements.

A protocol for characterizing chemical composition of exhaled breath in real time by using secondary nanoelectrospray ionization coupled to high resolution mass spectrometry is demonstrated.

利用二次 Nanoelectrospray 电离耦合高分辨质谱的实时呼吸分析

Exhaled volatile organic compounds (VOCs) have aroused considerable interest, since they can serve as biomarkers for disease diagnosis and environmental ...

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

The importance of understanding the fate of nitrate (NO3&#8722;), which is the dominant N species transferred from terrestrial to aquatic ecosystems, has been increasing because global nitrogen loads have dramatically increased following industrialization. Dissimilatory nitrate reduction to ammonium (DNRA) and denitrification are both microbial processes that use NO3&#8722; for respiration. Compared to denitrification, quantitative determinations of the DNRA activity have been carried out only to a limited extent. This has led to an insufficient understanding of the importance of DNRA in NO3&#8722; transformations and the regulating factors of this process. The objective of this paper is to provide a detailed procedure for the measurement of the potential DNRA rate in environmental samples. In brief, the potential DNRA rate can be calculated from the 15N-labeled ammonium (15NH4+) accumulation rate in 15NO3&#8722; added incubation. The determination of the 14NH4+ and 15NH4+ concentrations described in this paper is comprised of the following steps. First, the NH4+ in the sample is extracted and trapped on an acidified glass filter as ammonium salt. Second, the trapped ammonium is eluted and oxidized to NO3&#8722; via persulfate oxidation. Third, the NO3&#8722; is converted to N2O via an N2O reductase deficient denitrifier. Finally, the converted N2O is analyzed using a previously developed quadrupole gas chromatography&#8211;mass spectrometry system. We applied this method to salt marsh sediments and calculated their potential DNRA rates, demonstrating that the proposed procedures allow a simple and more rapid determination compared to previously described methods.

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

A series of methods to determine the potential DNRA rate based on 14NH4+/15NH4+ analyses is provided in detail. NH4+ is converted into N2O via several steps and analyzed using quadrupole gas chromatography&#8211;mass spectrometry.

基于14NH 4 + /4+ 15NH 4= 通过顺序转换为 N2O 的分析，测量异化硝酸盐降低至铵的潜在率

The importance of understanding the fate of nitrate (NO3&#8722;), which is the dominant N species transferred from terrestrial to aquatic ecosystems, has ...

Breath Collection from Children for Disease Biomarker Discovery

Breath collection and analysis can be used to discover volatile biomarkers in a number of infectious and non-infectious diseases, such as malaria, tuberculosis, lung cancer, and liver disease. This protocol describes a reproducible method for sampling breath in children and then stabilizing breath samples for further analysis with gas chromatography-mass spectrometry (GC-MS). The goal of this method is to establish a standardized protocol for the acquisition of breath samples for further chemical analysis, from children aged 4-15 years. First, breath is sampled using a cardboard mouthpiece attached to a 2-way valve, which is connected to a 3 L bag. Breath analytes are then transferred to a thermal desorption tube and stored at 4-5 &#176;C until analysis. This technique has been previously used to capture breath of children with malaria for successful breath biomarker identification. Subsequently, we have successfully applied this technique to additional pediatric cohorts. The advantage of this method is that it requires minimal cooperation on part of the patient (of particular value in pediatric populations), has a short collection period, does not require trained staff, and can be performed with portable equipment in resource-limited field settings.

This protocol describes a simple method for the acquisition of breath samples from children. Briefly, samples of mixed air are pre-concentrated in sorbent tubes prior to gas chromatography-mass spectrometry analysis. Breath biomarkers of infectious and non-infectious diseases can be identified using this breath collection method.

儿童疾病生物标志物发现的呼吸收集

Breath collection and analysis can be used to discover volatile biomarkers in a number of infectious and non-infectious diseases, such as malaria, ...

<meta charset="utf8"></head><body>一种实用且低成本的装置，用于测量水性样品中的甲烷

Measuring Dissolved Methane in Aquatic Ecosystems Using An Optical Spectroscopy Gas Analyzer

Measuring greenhouse gas (GHG) fluxes and pools in ecosystems are becoming increasingly common in ecological studies due to their relevance to climate change. With it, the need for analytical platforms adaptable to measuring different pools and fluxes within research groups also grows. This study aims to develop a procedure to use portable optical spectroscopy-based gas analyzers, originally designed and marketed for gas flux measurements, to measure GHG concentrations in aqueous samples. The protocol involves the traditional headspace equilibration technique followed by the injection of a headspace gas subsample into a chamber connected through a closed loop to the inlet and outlet ports of the gas analyzer. The chamber is fabricated from a generic mason jar and simple laboratory supplies, and it is an ideal solution for samples that may require pre-injection dilution. Methane concentrations measured with the chamber are tightly correlated (r2 &#62; 0.98) with concentrations determined separately through gas chromatography-flame ionization detection (GC-FID) on subsamples from the same vials. The procedure is particularly relevant for field studies in remote areas where chromatography equipment and supplies are not readily available, offering a practical, cheaper, and more efficient solution for measuring methane and other dissolved greenhouse gas concentrations in aquatic systems.

<meta charset="utf8"></head><body>使用光谱气体分析仪测量水生生态系统中的溶解甲烷

This study demonstrates an approach to measure methane gas concentrations in aqueous samples using portable optical analyzers coupled to an injection chamber in a closed loop. The results are similar to conventional gas chromatography, presenting a practical and low-cost alternative particularly suitable for remote field studies.

使用光谱气体分析仪测量水生生态系统中的溶解甲烷

Measuring greenhouse gas (GHG) fluxes and pools in ecosystems are becoming increasingly common in ecological studies due to their relevance to climate ...

快速，准确的呼出气测量氨

摘要

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使用光谱气体分析仪测量水生生态系统中的溶解甲烷