Introduction
Thin-layer chromatography, otherwise referred to as TLC, is a fast and inexpensive way to determine the amount of components in a solution or to identify an unknown compound. The principal behind TLC is when different compounds are placed on silica gel or alumina, (stationary phases) they will travel different distances when eluted with the proper solvent. According to ChemistryGuide, this is because the more polar compound has a stronger interaction with the silica gel due to its polar properties. This makes it easier to drive the eluent away from its binding area. An eluent is a liquid that allows a sample to move with it, from one place to another. On the other hand, nonpolar compounds generally consist of van der Waals dipole …show more content…
When referencing Figure 2, note that Table 2 was mistakenly spotted in lane 2 with the pure form of aspirin, therefore, this point is skipped when calculating the R_f value. Also, lane 3 was spotted with caffeine by mistake. In result, Table 2 claims that aspirin’s R_f value is .14, however, this is incorrect. This is actually caffeine’s R_f value that was calculated instead of aspirin. However, Figure 2 shows that in lane 3 aspirin has an R_f value between acetaminophen and ibuprofen. Therefore, this substance has a polarity in-between ibuprofen (low polarity) and acetaminophen (high polarity). Acetaminophen has a high polarity, this is known because the corresponding spot did not travel far on the silica gel. On the other hand, ibuprofen has a low polarity, which is known because the corresponding spot traveled the furthest on the TLC plate before …show more content…
When the spots are made too big, it makes the TLC plates difficult to read by causing the spots to overlap with other spots nearby. To ensure that the spots are not too big, use a spotting pipet calibrated to release only a certain amount of liquid. Also, in order to get more accurate results, if the mobile phase is not 1 cm from the top of the TLC plate after some time, add more eluent to the chamber. This will allow for more accurate results because the spots rely on the eluent for transport. Another way to improve this procedure could be to use a taller chamber. When the TLC plate was placed into the chamber, the TLC plate’s edges stuck out of the chamber. Therefore when placing aluminum foil on the chamber, the aluminum foil would rip allowing air flow through the
Thin-layer chromatography, otherwise referred to as TLC, is a fast and inexpensive way to determine the amount of components in a solution or to identify an unknown compound. The principal behind TLC is when different compounds are placed on silica gel or alumina, (stationary phases) they will travel different distances when eluted with the proper solvent. According to ChemistryGuide, this is because the more polar compound has a stronger interaction with the silica gel due to its polar properties. This makes it easier to drive the eluent away from its binding area. An eluent is a liquid that allows a sample to move with it, from one place to another. On the other hand, nonpolar compounds generally consist of van der Waals dipole …show more content…
When referencing Figure 2, note that Table 2 was mistakenly spotted in lane 2 with the pure form of aspirin, therefore, this point is skipped when calculating the R_f value. Also, lane 3 was spotted with caffeine by mistake. In result, Table 2 claims that aspirin’s R_f value is .14, however, this is incorrect. This is actually caffeine’s R_f value that was calculated instead of aspirin. However, Figure 2 shows that in lane 3 aspirin has an R_f value between acetaminophen and ibuprofen. Therefore, this substance has a polarity in-between ibuprofen (low polarity) and acetaminophen (high polarity). Acetaminophen has a high polarity, this is known because the corresponding spot did not travel far on the silica gel. On the other hand, ibuprofen has a low polarity, which is known because the corresponding spot traveled the furthest on the TLC plate before …show more content…
When the spots are made too big, it makes the TLC plates difficult to read by causing the spots to overlap with other spots nearby. To ensure that the spots are not too big, use a spotting pipet calibrated to release only a certain amount of liquid. Also, in order to get more accurate results, if the mobile phase is not 1 cm from the top of the TLC plate after some time, add more eluent to the chamber. This will allow for more accurate results because the spots rely on the eluent for transport. Another way to improve this procedure could be to use a taller chamber. When the TLC plate was placed into the chamber, the TLC plate’s edges stuck out of the chamber. Therefore when placing aluminum foil on the chamber, the aluminum foil would rip allowing air flow through the