*3.2.5 Analysis running*

Due to the laser spot size depending on the sample size, this spot is controlled by adjusting the magnification in the microscope objective lens (10x, 20x, 40x, or 50x) and the laser power. Laser radiation is triggered, and the laser beam is directed throughout the prisms (lens) of the system until the entrance of the microscope as shown in **Figure 6**. The samples placed inside the sample chamber are pyrolyzed by focusing the laser radiation directly through the objective of the microscope and, generating the pyrolysis products. Multiple shots are necessary on the particles to obtain enough pyrolysis products (**Figure 7**) to be then transferred online to interface between the sample chamber and GC system. This transfer is carried out via a heated transfer line at 300°C, using He as carrier gas. Pyrolysis products are continuously

#### **Figure 5.**

*Optical microscope equipment used to identify organic particles (a). Example of identification, selecting, and marking organic particles of Tasmanites algae (b, c) and solid bitumen (d, e) to LmPy-GC/MSMS analyses. Photomicrographs were taken under TWL (b, d) and FM (c, e).*

#### **Figure 6.** *Microscope receiving the laser beam (a) directed throughout lens (b) of the LmPy-GC/MSMS hyphenated system.*

#### **Figure 7.**

*Sample chamber at 300°C connected to an He flux interfacing (a) to transfer the pyrolysis products. Photomicrographs taken under TWL (b-d) and FM (e-g) showing the multiple shots on Botryococcus braunii particles.*

#### **Figure 8.**

*Transfer line (300°C) of pyrolysis products from the microscope to the PTV injector in GC/MSMS equipment (a). PTV injector (b) cooled at −80°C with liquid nitrogen (c).*

transferred to the PTV injector and then cryogenically entrapped in a cold trap (cryol collecting) using Liquid Nitrogen at −80°C.

Pyrolysis products are kept in the cold trapping long enough to ensure the complete trapping of the products from the sample chamber. After this time, the inlet temperature rapidly rises to vaporize the compounds and transfer the products to the Capillary GC Column. In this way, the pyrolysis products that were cryogenically entrapped at −80°C are heated up to 350°C and finally analyzed by GC/MSMS system (**Figure 8**).

*Using LmPy-GC/MSMS to Molecular Characterization of Organic Components… DOI: http://dx.doi.org/10.5772/intechopen.114360*
