lab 8 - Yichen Li Lab 8 Identification of an Adulterated...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Yichen Li 7/19/11 Lab 8: Identification of an Adulterated Herb or Spice by Thin Layer Chromatography Discussion Our group (#2) was given the unknowns 817, 818, 819, 820, where 820 was clearly the adulterant sample. I used 90% hexane and 10% ethyl acetate as my developing solvent for all the plates and observed the spots with UV light and Iodine chamber. For plate four, my group observed the TLC results for four samples, 817 (Caraway), 818 (Cloves), 819 (Cumin), and 820 (adulterant). We were able to identify and confirm these spices based on smell and appearance (color). On this plate, we were also able to see the differences in spots and identify the adulterant. 818 had a spot similar to that of 820’s, which had three spots. 818’s spot was UV and iodine active, with an R f value of 0.16. 820’s spot was also UV and iodine active with an R f value of 0.16. Thus, we identified that 818 was mixed into 820, along with another’s group’s pure H/S sample that is believed to be the adulterant. After looking at the class data, we found that licorice (813) matched up with our R f values (0.19 in UV and 0.15 in Iodine vs. 0.16 in UV and iodine) and both 820 and 813 were not spotted under DNPH. Also, 813 looked like it was in 820’s mixture because 818 was reddish brown whereas 813 was light tanned brown. Both samples, 820 and 813 smelled similar, providing more evidence that our prediction is accurate. On plate 5, I observed sample 820, 813, and 818 respectively. The results confirmed that
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/29/2011 for the course CHEMISTRY 3AL taught by Professor Pedersen during the Spring '10 term at Berkeley.

Page1 / 5

lab 8 - Yichen Li Lab 8 Identification of an Adulterated...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online