Before theanalysis process can begin, it is necessary to think carefully about which sample material is best suited for the respective analysis purpose. Why did the Aniveri Analysis decide on hair as the most suitable test material? Harald Hagendorfer, Deputy Managing Director and Head of Special Analytics at Ortho-Analytic, explains the differences between various sample materials.

In medical diagnostics, blood, urine or hair are usually considered for possible analysis in both humans and animals. We weighed up a number of considerations before choosing hair as the ideal test material for the Aniveri Analysis. This article explains why.

The choice of test material per se does not determine the substances that element analysis can investigate. It maps the exposure time during which there has been contact with certain minerals, trace and toxic elements and heavy metals.

Sample materials compared: Blood, urine or hair?

For example, if serum or plasma in the blood is analysed, the result reveals the acute condition. This might be about a few hours or even minutes, because everything absorbed is metabolised quickly and absorbed into the tissues, so it can no longer be detected. This sample material is only important in element analysis when there is acute intoxication.

It is similar with urine as a sample material, as long as the release of available metal ions is not “provoked” by the administration of chelating agents, which “bind” most heavy metals and also some toxic elements, enabling them to be excreted by the kidneys. Various chelates, such as DMPS (dimercaptopropane sulfonic acid), are used as complexing agents. These are used not only in the diagnosis of (toxic) metal exposure, but also in the treatment of acute poisoning, for example by arsenic or mercury. Amino acids containing sulphur, such as cysteine or methionine can also bind toxic metals and make them accessible to the kidneys. This class of substances also offers an interesting approach to the treatment of long-term but non-toxic exposure to heavy metals. Especially in the western hemisphere, this problem now represents the main route of exposure to toxic elements and heavy metals.

A graphic showing an overview of different sample materials and their exposure periods.
The selection of the sample material is determined by the time period during which the animal was exposed to the elements under investigation.

If whole blood or erythrocytes are analysed, a medium-term exposure time of days or weeks is revealed. Erythrocytes have a lifespan of around 120 days and can therefore show the status of ingested trace elements and toxic elements/heavy metals over a longer period of time.

Hair can be considered a bio-monitoring tool that represents an exposure period of weeks to months, or in very rare cases even years, depending on the length of the sample. So it can reveal a chronic exposure to toxic elements or a lack of trace elements and minerals. One popular human example is the famous composer Beethoven. About 200 years after he died, analysis of his hair revealed that he had been exposed to lead over a long period. It is very likely that this is what killed him eventually.

Hair as sample material: What can it reveal?

Hair analysis as a diagnostic tool is still often misunderstood. Hair is not a test material that can be used to detect acute poisoning. For this, bodily fluids such as serum, blood, plasma or urine are used. Hair is a very good test material for detecting long-term stress or nutrient supply.

Hair can be used effectively if chronic exposure to toxic elements or heavy metals is suspected. Scientific literature has given detailed descriptions of hair as an indicator of stressful situations. For example, the transfer of lead into the hair root can be detected well in the case of long-term exposure, even in the sub-toxic range. Trace elements in the hair can also be monitored, provided that care is taken to ensure that the hair is not contaminated with the elements from shampoos containing selenium or zinc wound creams. If products of this type are used regularly or not long before sampling, it can cause false positives in the analysis.

Until now, there has been debate about the determination of minerals. Tendencies and relationships can be estimated very effectively, allowing conclusions to be drawn about the supply of minerals.

Taking the hair sample

A hair goes through various growth phases. In the anagen phase it is growing, in the catagen phase it is in transition. The telogen or resting phase is the last stage before the hair finally falls out. In humans, it is assumed that 90 % of hair is in the anagen, i.e. growth phase. For the most part, hair grows constantly and can be removed at any time. Some older hairs in the telogen phase will always be present when the hair is removed. They do not interfere with the analysis, because by comparison they are so underrepresented that they cannot influence the results.

When taking the sample, it’s important to cut the hair straight from the roots, because you want to investigate the last few months. Older sections of hair can also be examined if previous exposure is suspected, for example to arsenic. Normal ranges are not optimized for the analysis of such sample material, as only a very high level of exposure can be detected, not a subchronic exposure. Ideally the hair should be taken from several places so that it can reveal the most comprehensive picture. A tablespoon or a pencil-thick amount of sample material is generally required for hair mineral analysis. This corresponds to around 200-300 mg, of which around 100 mg are used for the actual analysis. The rest is kept in the archive for ten years in case a follow-up analysis is necessary. The hair sample should be a maximum of four cm long.

The role of vets

For the Aniveri Analysis, ideally the vet cuts the hair, so that they conduct the pre-analysis process and the analysis delivers reliable results. It is always important to state whether, for example, zinc and selenium-containing medicinal dandruff shampoos or creams have been used, or if the hair has been treated with something as this can affect the measurement results. Vets should remove the hair from a less exposed area so that dust and dirt do not affect the analysis. The hair undergoes an extensive washing procedure before the analysis, but the analysis is still more reliable if the animal’s hair is not very dirty.