Peele G L, Brent D A
Biomed Mass Spectrom. 1978 Mar;5(3):180-3. doi: 10.1002/bms.1200050303.
Field desorption mass spectra often contain few peaks, the largest of which are [M]+. and [M+H]+ ions. Because of this lack of fragmentation accurate mass measurement is of primary concern in field desorption mass spectrometry. Although total ion yield per quantity of sample may rival electron impact or chemical ionization methods, ion yield per unit time is low. For this reason and because of varying [M]+./[M+H]+ ratios, elemental compositions as determined from stable isotope peaks are difficult to obtain. Low ion yield per unit time demands an integrating method for best high resolution results. The use of photoplates to obtain high resolution field desorption data is the only method reported thus far which takes advantage of integrating capability. This paper describes the use of a time averaging computer as an integrator for peak matching high resolution field desorption mass spectrometry using electrical detection. Accuracies better than 20 ppm are consistently obtained. Due to the sensitivity of the technique a wider range of reference compounds can be employed. This method incorporates the advantages of integrating capability with electrical detection, overcoming detection sensitivity problems associated with photoplates.
场解吸质谱通常包含很少的峰，其中最大的峰是[M]+和[M + H]+离子。由于缺乏碎片，精确质量测量在场解吸质谱中是首要关注的问题。尽管每单位样品的总离子产率可能与电子轰击或化学电离方法相当，但单位时间的离子产率很低。由于这个原因以及[M]+/[M + H]+比率的变化，通过稳定同位素峰确定的元素组成很难获得。单位时间的低离子产率需要一种积分方法以获得最佳的高分辨率结果。使用光板来获得高分辨率场解吸数据是迄今为止报道的唯一利用积分能力的方法。本文描述了使用时间平均计算机作为积分器，用于通过电检测进行峰匹配的高分辨率场解吸质谱分析。始终能获得优于20 ppm的准确度。由于该技术的灵敏度，可以使用更广泛的参考化合物。该方法结合了积分能力和电检测的优点，克服了与光板相关的检测灵敏度问题。
