The Research Institute of Advanced Technologies, Ningbo University, Ningbo, 315211, Zhejiang, China; China Innovation Instrument Co., Ltd, Ningbo, 315000, Zhejiang, China.
The Research Institute of Advanced Technologies, Ningbo University, Ningbo, 315211, Zhejiang, China; Department of Chemistry, University of Dhaka, Dhaka, 1000, Bangladesh.
Talanta. 2021 Jan 15;222:121673. doi: 10.1016/j.talanta.2020.121673. Epub 2020 Sep 18.
In analytical mass spectrometry, an efficient desorption is needed for nonvolatile compounds at ultra-trace level detection. In this paper, an ultrasonic cutter-assisted non-thermal desorption method for ultra-trace level detection of different types of nonvolatile compounds such as drugs of abuse, explosives, pharmaceuticals, spinosad, cholesterol, rhodamine B, glucose and amino acids has been described. The relevant compounds were deposited on the ultrasonic blade except pharmaceutical tablets that were used directly, and gently touched on perfluoroalkoxy (PFA) made substrate with oscillation frequency about 40 kHz in order to desorb the solid molecules. The desorbed gaseous molecules were ionized using a home-made helium dielectric barrier discharge ionization (DBDI) source and then detected by an ion trap mass spectrometer. The synergistic effect caused by gaining the oscillation and frictional/mechanical energy enhanced desorption of the solid molecules into gaseous phase, thereby, resulting in detection at ultra-trace level. PFA made substrate showed better limits of detection (LODs) compared to that of wood made substrate. The LOD values for most of the target analytes were ranging from 20.00 ± 0.91 to 200.25 ± 9.04 pg with RSD values ≤ 5% except for pharmaceutical tablets where only depletion amounts were estimated. The LOD value of cocaine in urine was 39.88 ± 1.65 pg with RDS ≤4.56% showed to be a very promising analytical tool for analysis of drugs of abuse in biological samples under ambient conditions. Drugs of abuse, pharmaceuticals, spinosad, cholesterol, rhodamine B, glucose and amino acids were detected mostly as their protonated molecular ions while RDX and HMX were detected as their molecular cluster/adduct ions as [M + NO2]- and [M + NO3]-, and AN was detected as a cluster ion of HNO3 with NO3-, [HNO3 + NO3]-, without suffering from fragmentation. An effective mechanism of the enhanced sensitivity of the tribodesorption-DBDI-MS system in analyzing the nonvolatile compounds has been discussed.
在分析质谱中，需要高效地解吸痕量水平下的非挥发性化合物。本文描述了一种超声刀辅助的非热解吸方法，用于超痕量水平检测各种类型的非挥发性化合物，如药物滥用、爆炸物、药物、螺虫乙酯、胆固醇、罗丹明 B、葡萄糖和氨基酸。相关化合物沉积在超声刀片上，除了直接使用的药物片剂，还以约 40 kHz 的振荡频率轻轻接触全氟烷氧基（PFA）基底，以解吸固体分子。解吸的气态分子使用自制的氦介质阻挡放电电离（DBDI）源进行电离，然后用离子阱质谱仪进行检测。通过获得振荡和摩擦/机械能量的协同作用，增强了固体分子向气相的解吸，从而实现了痕量检测。与木质基底相比，PFA 基底显示出更好的检测限（LOD）。大多数目标分析物的 LOD 值范围为 20.00 ± 0.91 至 200.25 ± 9.04 pg，RSD 值≤5%，除了药物片剂，仅估计了耗尽量。尿液中可卡因的 LOD 值为 39.88 ± 1.65 pg，RDS≤4.56%，在环境条件下分析生物样品中的药物滥用物，这是一种非常有前途的分析工具。在分析生物样品中的药物滥用物、药物、螺虫乙酯、胆固醇、罗丹明 B、葡萄糖和氨基酸时，主要检测到它们的质子化分子离子，而 RDX 和 HMX 则作为它们的分子簇/加合物离子[M+NO2]-和[M+NO3]-检测，而 AN 则作为含有 NO3-的 HNO3 簇离子[HNO3+NO3]-，没有发生碎裂。讨论了增强的摩擦解吸-DBDI-MS 系统分析非挥发性化合物的灵敏度的有效机制。
