Cracow Institute for Forensic Research: Methodology, Part I

Methodology: Part I

Samples, about 1-2g in weight, were taken by chipping pieces from bricks and concrete or scrapping off, particularly in the case of plaster and also mortar. The materials taken were secured in plastic containers marked with serial numbers. All these activities were recorded and documented with photographs. Work connected with them took the commission two days. The laboratory analysis of the material collected was conducted – to ensure full objectivity – by another group of Institute workers. They started with preliminary work: samples were comminuted by grinding them by hand in an agate mortar, their pH was determined at 6 to 7 in nearly all samples. Next the samples were subjected to preliminary spectrophotometric analysis in infrared region, using a Digilab FTS-16 spectrophotometer. It was found that the bands of cyanide groups occurred in the region of 2000-2200 cm-1 in the spectra of a dozen samples or so. However, the method did not prove to be sensitive enough and was given up in quantitative determinations. It was determined, using the spectrographical method, that the main elements which made up the samples were: calcium, silicon, magnesium, aluminium and iron. Moreover, titanium was found present in many samples. From among other metals in some samples there were also barium, zinc, sodium, manganese and from non-metals boron.

The undertaking of chemical analysis had to be preceded by careful consideration. The revisionists focussed their attention almost exclusively on Prussian blue, which is of intense dark-blue colour and characterized by exceptional fastness. This dye occurs, especially in the form of stains, on the outer bricks of the walls of the former bathdelousing house in the area of the Birkenau camp. It is hard to imagine the chemical reactions and physicochemical processes that could have led to the formation of Prussian blue in that place. Brick, unlike other building materials, very feebly absorbs hydrogen cyanide, it sometimes does not even absorb it at all. Besides, iron occurring in it is at the third oxidation state, whereas bivalent iron ions are indispensable for the formation of the [Fe(Cn)6]-4 ion, which is the precursor of Prussian blue. This ion is, besides, sensitive to the sunlight.

J. Bailer (1) writes in the collective work “Amoklauf gegen die Wirklichkeit” that the formation of Prussian blue in bricks is simply improbable; however, he takes into consideration the possibility that the walls of the delousing room were coated with this dye as a paint. It should be added that this blue coloration does not appear on the walls of all the delousing rooms.

We decided therefore to determine the cyanide ions using a method that does not induce the breakdown of the composed ferrum cyanide complex (this is the blue under discussion) and which fact we had tested before on an appropriate standard sample. To isolate cyanide compounds from the materials examined in the form of hydrogen cyanide we used the techniques of microdiffusion in special Conway-type chambers. The sample under examination was placed in the internal part of the chamber and next acidified with 10% sulfuric acid solution and allowed to remain at room temperature (about 20°C) for 24 hrs. The separated hydrogen cyanide underwent a quantitative absorption by the lye solution present in the outer part of the chamber. When the diffusion was brought to an end, a sample of lye solution was taken and-the pyridine-pyrazolone reaction carried out by Epstein’s method (3). The intensity of the polymethene dye obtained was measured spectrophotometrically at a wavelength equal to 630nm. The calibration curve was constructed previously and standards with a known CN- content were introduced into each series of determinations to check the curve and the course of determination. Each sample of materials examined was analysed three times. If the result obtained was positive, it was verified by repeating the analysis. Having applied this method for many years, we have opportunities to find its high sensitivity, specificity and precision. Under present circumstances we established the lower limit of determinability of cyanide ions at a level of 3-4 ,µg CN- in 1 kg of the sample.

The results of analyses are presented in Tables I-IV. They unequivocally show that the cyanide compounds occur in all the facilities that, according to the source data, were in contact with them. On the other hand, they do not occur in dwelling accomodations, which was shown by means of control samples. The concentrations of cyanide compounds in the samples collected from one and the same room or building show great differences. This indicates that the conditions that favour the formation of stable compounds as a result of the reaction of hydrogen cyanide with the components of the walls, occur locally. In this connection it takes quite a large number of samples from a given facility to give us a chance to come upon this sort of local accumulation of cyanide compounds.