Investigation Ideas : Obtain additional references/resources Design investigations:

1. Huang Na’s Last Meal -adapted for chemical analysis Case synopsis An 8-year old girl was reported missing. The prime suspect, Beng, was one of the persons interviewed by the police after her disappearance. It was known that Beng had bought some mangoes close to the time of her disappearance. Three weeks later, the girl’s body was found. The pathologist concluded that she was strangled to death. Some yellowish-brown residues were recovered from her stomach. The police suspected that Beng had offered mango to the girl as bait. The stomach residues were submitted to the head of chemistry section, who called a staff meeting to discuss how to identify the stomach residues. • Learning Objectives: • Identification of appropriate analysis method • Sampling • Sample pretreatment/preparation : Extraction • Reference sample • Instrumentation – HPLC • Some Other Useful Resources: • Online – video on analytical techniques http://www.youtube.com/watch?v=kz_egMtdnL4&feature=related • Website on forensic analysis of stomach contents http://www.exploreforensics.co.uk/stomach-contents-as-a-means-of-evidence.html • Investigation: • Instructor treats fresh mangoes, pineapples and papayas, respectively with simulated stomach juices for 3 weeks. • Students are given treated mango samples as reference standard. • They are given treated mangoes, pineapples or papayas as “recovered stomach contents”. • Students are to obtain HPLC chromatograms of standard and “stomach contents” and make deductions about the stomach contents. • Investigation Ideas : • Obtain additional references/resources • Design investigations: • Chemical changes to carbohydrates in stomach • How to simulate stomach conditions • Spectroscopic analysis of HPLC fractions • Toxicity of local fruits http://www.labwrench.com/?equipment.view/equipmentNo/4072/Waters/Alliance-HPLC/ http://www.naturespride.eu/our-products/product-detail/mango/