Biological samples precautions with

If a biological sample such as the urine is considered a bio-hazard, take the necessary handling precautions associated with bio-hazardous materials. 

Whatever the source of radiation used, the dose delivered to the biological samples is determined by the time of exposure to radiations. Thus the dose delivered by the radiation source must be measured with precision. Dosimetry can be performed with a ferrous sulfate solution (Fricke and Morse, 1927), thermoluminescent dosimeters, bleaching of films (Hart and Fricke, 1967), Perspex dosimetry (Berry and Marshall, 1969), or calibration with standard enzymes (Beauregard et al., 1980 Beauregard and Potier, 1982 Lo et al., 1982). In many laboratories, control enzymes with known D37 are added to protein preparations as internal standards so that any variation between experiments could be corrected for. Because of the better precision of dose rate in Gammacell irradiators, this precaution is not necessary. 

Another factor of importance in the choice of a fractionation technique is the sensitivity of the detection technique because the total concentration of some trace elements in biological samples lie at the limit of detection of most conventional techniques. Therefore fractionation methods in which the species are extensively diluted can only be used for these elements when it is possible to concentrate the fractions afterwards. Current technology enables analyte concentrations of about 1 fig/L to be determined in biological matrices. However, at these levels special precautions have to be taken to avoid contamination from external sources, and it is difficult to establish the accuracy of the determination. At present the speciation of metals or metalloids present at total levels less than 100 fig/L can only be undertaken with time-consuming and tedious methods which increase the probability of altering the metal-ligand interaction. 

Damage to biological samples by X-rays is cause for serious concern for XAS experiments. However, with the right precautions one can successfully perform these experiments, leaving the materials largely intact. The most serious damage is produced by the reaction with free radicals... 

Relatively little is known about the effects of storage on the stability of methylmercury in biological samples. Significant external contamination of samples with methylmercury is unlikely to occur however, extreme precautions are necessary to avoid contamination by inorganic mercury. 

Precautions Compartment 6 contains 75 iL of 10 N NaOH avoid contact skin irritant rinse contacted area with water. Comply With OSHA s Bloodbome Pathogens Standard While Handling Biological Samples (29 CFR 1910.1039). 

The possibility of contaminating the sample with the elements under investigation during the various steps is a major risk in trace analysis. The precautions required in order to minimize this problem are similar to those already identified when dealing with biological materials used for total element determinations. Heydom Ver-sieck et al. Stoeppler Behne and Aitio et al. have diam ed the extent... 

Workup in the lab should use standard precautions for working with compounds of unknown biological properties. Caution should be taken not to expose oneself to the compounds in any way. Wear gloves when necessary, work in chemical fiime hoods, prevent contact of any compounds with the skin, do not ingest any of the sample, and do not smell the sample directly. If for some reason, the sample must be smelled (the author recommends that you don t), use normal chemical precautions, and waft the vapor towards your nose in order to minimize exposure. 

The problems in the determination of manganese in biological material have been highlighted in many papers in the literature, as reviewed in this chapter. Despite this, papers still appear with data that is of little value because the proper precautions in sampling and determination were not taken. There are emerging now reliable values for normal levels of manganese in body fluids and tissues new studies should show control values which are similar to these. 

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