Laser desorption-ion mobility spectrometry as a useful tool for imaging of thin layer chromatography surface

Low-Temperature Plasma Probe Mass Spectrometry for Analytes Separated on Thin-Layer Chromatography Plates: Direct vs Laser Assisted Desorption

“…Thus, the isolated ions at m / z 130 were used for quantitation. In general, a 2 to 4 orders magnitude improvement in the LODs was obtained, which is better than any of the LODs reported to date on plasma-based ambient desorption ionization MS from TLC plates, as discussed in the previous sections. ,,,, In addition, the LODs in Table are also comparable to the performance reported for amino acids with MALDI-TOF-MS . It needs to be pointed out that in that study standard solutions were directly pipetted on the MALDI sample plate, not on TLC plates where the desorption is affected by the strong interaction between the analyte and the TLC matrix, and using internal standards for quantitation.…”

“…The LODs ranged from 0.6 to 27.7 ng/mm 2 (5.3–266 ng per sample spot), which are comparable, or better, to LODs reported using other diode laser TLC-MS techniques. For example, LODs of 10 ng for proline and 3 μg for isoleucine were reported for diode laser desorption corona discharge ion mobility spectrometry (CD-IMS) from silica gel TLC plates . The LODs obtained here by the developed LD-LTPMS approach are 0.9 ng/mm 2 (9 ng per sample spot) for proline and 1.5 ng/mm 2 (14.5 ng per sample spot) for isoleucine (Table , laser spot diameter 0.34 mm), which is comparable for proline and several orders of magnitude better for isoleucine in contrast to the CD-IMS technique.…”

“…For example, the LOD of DART-MS, with helium discharge gas heated up to 250 °C, was estimated to be in the higher picogram-range for isopropylthioxanthone (ITX) from NP-TLC plates based on the detectability of 1.3 ng of ITX spotted on the plate (with S/N of 84) . In addition, LODs in the range of 3–80 ng for five explosives were reported for diode laser desorption CD-IMS . Also, an LOD of 10 ng per spot of a pyrazole derivative was obtained by using diode laser combined with FAPA-MS .…”

Thin Layer Chromatography as Innovative Technique for Qualitative Characterization of Biodiesel Produced by Esterification

“…Moreover, TLC allows the determination of the purity of a compound, identification of the components in a mixture, isolation of pure components of a solution and monitoring of the progress of the reaction by the appearance of products and the disappearance of reagents (ILBEIGI et al, 2016;MARTELANC, VOVK e SIMONOVSKA 2009). The main advantages of applying TLC include ease comparison and utilization, separation of components within a short period of time, versatility and, especially, low operational costs involved in the process because it works at milder pressures and temperatures (MROCZEK et al, 2006;RISTIVOJEVIC´ et al, 2017).…”

“…In the method of iodine vapor visualization, the iodine in the form of dust reacts with the compounds of the sample, forming brown (product) or yellowish (raw material) complexes. The advantage of the method is that the metal complexes with unsaturated compounds, while through UV, compounds appear as bright spots when they are under the action of UV light (ILBEIGI et al, 2016;MROCZEK et al, 2006). The disadvantage of the iodine vapor visualization method is the fact that the sample cannot be recovered, because a chemical reaction has occurred.…”