Let's check it out:
Family: Ranunculcaceae Scientific name:Aconitum spp Common name: monkshood Found in: forests, nartural areas, moist wood, along creek banks, landscape, flower gardens
It can be used as herbs!
SO.... can we eat it now?
Poisonous parts: ALL
Severity: FATAL if ingested
Aconite is a plant
of the genus Aconitum. Aconitine is a
toxic derived from the Aconitum genus plant. Aconitine is high in toxicity and aconitine poisoning is usually caused by consuming Chinese herbal medicine or by eating aconite the plant itself.
The usual causative agents of aconite poisoning are the Aconitines which comprise of aconitine, hypaconitine, jesaconitine and mesaconitine.) It is estimated the Lethal Dose, 50% (LD50) of aconitine for humans is 1-2mg/kg.
This toxic acts on sodium channels in excitable membrane. The symptoms of aconitine poisoning are nausea, vomiting, numbness in limbs and arrhythmia. This poisoning often result in death due to cardiac arrest. So how do we detect it in samples?
The instrument we used here to identify and quantify trace aconitine in deceased sample is LC-MS, which is HPLC (High Performance Liquid Chromatography) coupled with MS (Mass Spectrometry).
This method allows physical separation of components by HPLC and also mass analysis by MS. With this technique, high selectivity and sensitivity applications are performed.
HPLC (high performance liquid chromatography)
A higher improved form of column chromatography. High pressure is used to force the solvent down the column, which makes it much faster. Physical separation of compounds is based on the interaction between the stationary phase and the analytes. HPLC allows smaller particle size for column packing material which gives a much larger surface area for better separation.
MS (mass spectrometry)
An analytical method where components, after being separated by HPLC or other separation techniques, will undergo ionization to generate charged molecules/fragments and the identity of each component will be determined based on the distribution of the fragments' mass to charge ratios.
In this way, accurate and precise quantitative and qualitative results can be achieved by coupled LC-MS (HPLC-MS).
As the mass spectrometry technique is new and foreign, this is a video behind to how it works.
Link: http://www.youtube.com/watch?v=tOGM2gOHKPc
Summary: Sample is auto injected into HPLC Sample passes through column to be separated (usually by reversed phase) Metabolites at the end of the column will enter the mass spectrometer They are ionized and form positively charged ions The ions are deflected and separated by electromagnetic field according to mass-to-charge ratios. The beam of ions that passes through is detected electrically.
·Mobile phase (formic acid of HPLC grade,
acentonitrile of LC-MS grade)
·Methyllycaconitine (Internal Standard)
·Aconitines (Aconitine, Mesaconitine,
Hypaconitine and Jesconitine)
·Deceased Urine Sample
·2mL of 0.025% (v/v) ammonia solution
· Aconitine Standards
For the Mobile phase,
Mix formic acid of 0.1% (v/v) with acetonitrile (solution
1). Mix formic acid of 0.1% (v/v) with aqueous solution (solution 2). Mix solution
1 with solution 2 to a ratio of (24:76, v/v).
For Urine sample,
We chose to take urine sample instead of serum sample as according
to research, aconitines will not retain in serum after 24 hours of ingestion. However,
it is still detectable in the urine after 23-62hours.
To prepare the sample, mix one milliliter of urine sample with
2.5ng of Methyllycaconitine (I.S) and 2 mL of 0.0025% (v/v) ammonia solution.
To prepare blank urine sample : Purify from deceased's urine sample using urine purification kits. Removal of nucleic acids and proteins.
For preparatation of standards: mix one mililiter of respective aconitine with 2.5ng of Methyllycaconitine (I.S) and 2 mL of 0.0025% (v/v) ammonia solution.
*Prepare 4 sets of urine sample as test will be run thrice and average result will be taken for a fair test. ( 3 urine samples from deceased, and a blank urine sample as control)
*Prepare 3 standards for each aconitines (aconitine, hypaconitine, jesconitine, mesaconitine) according to the table below:
Mesaconitine, Aconitine and Jesaconitine identified in deceased's urine sample.
(IDENTITY APPROVED)
Quantitive analysis: Calculation of concentration of Mesaconitine, Aconitine, Jesaconitine in Urine sample
We calculate the (Ratio of standard aconitines/ Internal standard) by using the peak areas. With this results, we will be able to plot the calibration graph (Ratio of standard aconitines/ Internal standard against concentration of each of the Aconitines (Mesaconitine, Aconitine, Hypaconitine, Jesaconitine) by using the 3 standards.
After the calibration graph is plotted, we will have linear equations for each of the 4 aconitines. This equation will be used to calculate the concentration of Mesaconitine, Aconitine, Jesaconitine in the deceased's urine sample. Thus, we will be able to quantitate trace amount of any of the aconitines present in the urine sample, and determine which is the highest concentration as well.
A packet of Aconitine tampered sweets were found in Mary Rose's bag....
Did she put it herself??? Is she considering suicide? Or a homicide?
POLICE REPORT
Suspect: Ramley Busher
Relation to victim: Colleague working in ABC Enterprise
Suspected motive: Being threaten by victim with evidence showing that he stole company's confidential information and selling it to other company. After paying a big sum of money, victim is still not satisfied and asked for more money. He did not want to be threatened anymore and decide to kill her.
Plot: Sent a packet of victim's favorite sweet which is only available in Canada in the name of the victim's distant relative staying in Canada. The packet of sweets is already tampered with Aconitines. He then told her to meet at the hill for the transaction. He purposely did not reach in time, he knew the victim will have a few of that sweets while waiting. After ingesting at least 2 sweets, victim is poisoned and tried to call for help, but is helpless. Leaving her in the car waiting for her heart to stop. This is to purposely make police think that victim died of carbon monoxide poisoning.
A case of HOMICIDE
After several investigations and trials, Busher has admitted to the murder of Mary Rose by aconitine poisoning. He will be charged with Lifelong Imprisonment.
Fujita, Y., Terui, K., Fujita, M., Kakizaki, A., Sato, N., Oikawa, K., Aoki, H., & Takahashi, K. (2007, April ). Five cases of aconite poisoning: Toxicokinetics of aconitines. Retrieved from http://jat.oxfordjournals.org/content/31/3/132.full.pdf
