Non-essential, toxic trace elements

The concentrations in body fluids of trace elements with no known biological functions for maintaining optimal human health, and which are toxic at relatively low concentrations are listed in Table 3. Measurements of these concentrations can be important in monitoring the health of populations occupationally exposed to these elements and in surveys to determine the extent of possible environmental contamination. 

Molecular absorption interferences can be reduced considerably by ashing within the atomiser itself, although care must be taken to avoid preatomisation losses of lead which occur at 350—400°C with untreated blood samples. These losses may be avoided at higher temperatures by the addition of a solution of (NH4)2HP04 [111]. The net effect of the sample matrix on 

CONCENTRATIONS OF NON-ESSENTIAL, TOXIC TRACE ELEMENTS IN BODY TISSUES AND FLUIDS 

Element (units) Physiological concentrations eta-aas sensitivity Volume required for analysis11 

The most useful index of excessive exposure to lead is a blood-lead analysis, and the majority of methods discussed here are concerned with this measurement. Many of the earlier ETA—AAS methods used little or no sample pretreatment and in almost all cases the variety of matrix interferences encountered necessitated strict control of ETA conditions, and made calibration by standard additions mandatory. The problem of diffusion of liquid blood samples into the graphite atomisers was overcome as an 

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