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膜进样质谱仪 智能水质在线监测系统
具体成交价以合同协议为准
2024-11-11上海
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产品简介
美国自然基金委推荐测量湿地脱氮速率专用仪器反硝化速率和脱氮速率科研的强大工具高精度溶解气体测量仪器前言：氮气（N2）、氧气（O2）、二氧化碳（CO2）是湿地、河流、湖泊、海洋等水体中的重要溶解气体，是生态环境变化过程中的重要参数指标
详细信息
美国自然基金委推荐测量湿地脱氮速率专用仪器
反硝化速率和脱氮速率科研的强大工具
高精度溶解气体测量仪器
前言：
氮气（N2）、氧气（O2）、二氧化碳（CO2）是湿地、河流、湖泊、海洋等水体中的重要溶解气体，是生态环境变化过程中的重要参数指标。例如，溶解氧是衡量海气扩散过程、水团混合、大洋环流以及海水中生物化学过程的重要指标；水体中CO2对于研究碳循环和气候变化具有重要作用；而水体中溶解N2则对于研究水体反硝化速率、农业氮肥利用率、水体富营养化等相关问题具有至关重要的作用。目前，测量水体海洋中溶解气体的传统方法是先采集水样，然后在实验室内或者船上进行检测，但由于很多参数会随时空的变化而发生改变，从而得不到实时原位的准确数据。水体及沉积物反硝化速率的测定方法主要有乙炔抑制法、N2通量法、质量平衡法、化学计量法和同位素法，但这些方法大多存在人为扰动大、操作繁琐、误差大的不足，因而无法精确测定淹水环境下的反硝化速率。膜进样质谱仪（MIMS）则能够实时、原位、连续监测水体中的溶解气体（N2、O2、CO2），并且能够精确测定淹水环境下水体、沉积物的反硝化速率，已被国内外众多研究机构广泛应用，并被美国自然科学基金委推荐用来测定湿地脱氮速率。同时，膜进样质谱仪还能够应用于稳定同位素（15N 、18O、13C）的检测、光合呼吸、生物反应器等方面的研究。
主要特点：
- 可实时、原位检测
- 测量精度高、重复性好
- 所需样品量少，仅5ml
- 操作简便，样品分析快，仅90s
- 不需要顶空平衡，可实现水气分离
- 可将空气中高浓度背景气体分离开，避免了样品的污染
- 专用软件（QuickData）高效评估收集的信号和数据
图1 QuickData软件
主要应用：
- 环境（水体、沉积物）反硝化速率的研究
- 原位测量水体（海洋/湖泊/河流/地表水/地下水）中O2、CH4、DMS、CO2和Ar浓度
- 海洋总初级生产力的测定
- 贫瘠水域的呼吸作用研究
- 稳定同位素的测定（15N 、18O、13C）
图2 MIMS在反硝化中的应用，将原状沉积物和上覆水取回在室内进行培养，研究反硝化过程中N2的排放速率
图3 利用已知CH4浓度和测量出来的信号值进行拟合曲线，进而测量未知水体中CH4浓度
图4 MIMS可用于水生生态系统代谢和氧气动力学研究
图5 MIMS可与液相氧电极或叶绿素荧光仪联用测量光合和呼吸作用
MIMS典型应用：
表1 标样连续测定10h后信号偏移情况（李晓波等，2013）
表2 MIMS与IRMS在测量海洋总初级生产力时的数据比较
图7 利用MIMS测量出11种中国典型稻田土壤下的反硝化、厌氧氨氧化、DNRA的贡献率（Shan J et. al, 2016）
参考文献：
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2.赵永强, 夏永秋, 李博伦, 等. 利用膜进样质谱同时测定河流沉积物反硝化和厌氧氨氧化. 农业环境科学学报, 2014, 33(4): 794-802
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