External examination of the body revealed areas of hyperpigmentation and white lines (Mee’s lines) across the fingernails. As well, hair was falling from the scalp (alopecia). A fecal sample had a smell of garlic and there was evidence that the victim vomited (in waste basket). As these observations are all consistent with arsenic poisoning, toxicological examination for arsenic was ordered.

Gutzeit Test:

The Gutzeit test is a simple colorimetric analysis that involves the detection by mercuric bromide (Hg₂Br₂) of arsine gas (AsH₃) released from the reaction of arsenic trioxide (As₂O₃) with hydrogen gas. The mercuric bromide is impregnated onto strips of filter paper. If arsine gas is produced, the filter paper will turn yellowish/red and is relatively quantitative. The victim’s blood serum, extracted gastric contents as well as samples of the vomit in the wastebasket were tested for the presence of arsenic with the following results:

Gutzeit Sample Key A = blank control B = Vomit from wastebasket C = Blood sample D = Stomach contents
		Sample A	Sample B
		Sample C	Sample D

Compared to the blank control, all samples were positive from arsenic. Relatively speaking, the vomit in the wastebasket contained the highest concentration of arsenic with the lowest concentration in the blood.

Because the Gutzeit test was positive for arsenic, food samples from the office were also tested for the presence of arsenic. Of all samples, only the chocolate brownies and 10X Confectioner’s sugar were positive for arsenic.

Because there was a positive Gutzeit reaction, post-mortem as well as the food samples were sent to the MIT Nuclear Laboratory crime lab for neutron activation analysis in order to confirm the presence of arsenic.

NAA (Neutron Activation Analysis):

NAA involves the bombardment of a sample with neutrons. Once a sample (atom) takes up a neutron, it becomes radioactive and emits gamma radiation. The radiation emitted is characteristic of the atom that incorporated the neutron and therefore can be used to determine the presence of up to 30 different elements.

NAA Results (where indicated, normal values of arsenic are listed):

H1-H10 represent 1 mm sections of the decedent’s hair (H1 next to scalp and H10 furthest from scalp). After 1cm of growth from the scalp, no detectable amounts of arsenic above the normal level were discovered.

As arsenic absorption is fairly rapid and the amount of arsenic in each hair sample represents the amount of arsenic in the blood at the time that the hair was made, a timeline of arsenic consumption can be constructed. Because on average hair grows at a rate of about 1.5cm (15mm) per month, each millimeter sample represents about 2 days. Therefore, approximately 2-3 weeks prior to her death, the victim was exposed to her first dose of arsenic. As well, approximately a 4X increase in arsenic consumption (arsenic concentration in hair closest to scalp) was the probably cause of death.