Exploratory study on chemical compounds related to pulmonary hypertension

热解吸系统(TDS)常用于分析化学领域。大气压电离质谱仪(APIMS)可以检测到非常低水平的气体化合物。TDS和APIMS的联合使用有可能检测到体内低水平的代谢物。在本研究中，我们开发了一种新的TDS，用于APIMS的生物学应用。开发的系统主要由质量流量控制器、气体净化器和热解吸管组成，在热解吸管中，净化后的气体通过放置在装有石英棉热源的较大管中的毛细管。热传感器连接到管子的表面，管子周围环绕着一个卷曲的加热器。载气的温度分布由温度调节器在给定的模式下控制。在保持恒定混合比的情况下，解吸出的气体用相同的载气稀释并引入APIMS。载气的温度略低于…高于温度调节器的温度设置，但以10 oC/分钟的速率很好地遵循了它。接下来，我们将TDS-APIMS系统应用于溶液和血液中乳酸的测定。将一微升样品放入毛细管中，毛细管被初步烘烤。利用APIMS的负电荷模式分析了乳酸离子的质谱图。乳酸离子在相对较低的温度下解吸，低于其沸点，在APIMS的电离室中很容易带入电子。89(CH3CHOHCOO-)的m/z峰离子强度随浓度的增加而增加，在10-5~10-4M范围内呈线性关系，乳酸(阴离子)的检出限为1.0×10-5M。在这两个电离态中，光谱都得到了很好的重现。综上所述，为高灵敏度大气压电离质谱仪的生物应用开发了一种新型的热解吸系统。TDS-APIMS系统成功地检测到低质量数的游离有机化合物，如纳升体积的血液中的乳酸。较少

Thermal desorption systems (TDS) are often used in the field of analytical chemistry. Atmospheric pressure ionization mass spectrometers (APIMS) can detect very low levels of gaseous compounds. The combined use of TDS and APIMS has the potential of detecting low levels of metabolites in the body. In the present study, we developed a new TDS for the biological application of APIMS. The developed system consists mainly of mass-flow controllers, gas cleaners and a thermal desorption tube in which the cleaned gases pass through capillary tubes placed within a larger tube packed with a quartz wool heat source. A heat sensor was attached to the surface of the tube, which was surrounded by a coiled heater. The temperature profiles of the carrier gas were controlled by a thermo-regulator at a given pattern. While maintaining a constant mixing ratio, the desorbed gas was diluted with the same carrier gas and introduced into the APIMS. The temperature of the carrier gases were slightly lower tha … More n the temperature setting of the thermo-regulator, but followed it well at a rate of 10 oC /min. We next applied the TDS-APIMS system to the measurement of lactate in solution and in blood. One micro liter of samples was put inside a capillary tube, which was preliminarily baked. The mass spectrum of lactate ions was analyzed using the negative charge mode of the APIMS. Lactate ions was desorbed at a comparatively low temperature, below its boiling point, and easily charged with electrons in the ionization chamber of the APIMS. The peak ion intensity at the m/z of 89 (CH3CHOHCOO-) increased in a concentration-dependent manner, and exhibited a linear relation within the ranges of 10-5 to 10-4 M. The detection limit of lactic acid (anion) was 1.0 x 10-5 M. Rat plasma was also analyzed in both positive and negative ion charges modes. In both ionization states the spectrums were well reproduced. In conclusion, a new type of thermal desorption system was developed for the biological application of an atmospheric pressure ionization mass spectrometer with high sensitivity. The TDS-APIMS system successfully detected free organic compounds with low mass numbers, such as lactic acid in nano-liter volumes of blood. Less