The poisonous effect of heavy (toxic) metals like mercury (Hg), cadmium (Cd), arsenic (As) & lead (Pb) is well documented in specialized literature. For example, excessive exposure to lead (Pb), from the environment, workplace, or home, can affect nearly every system in the body, and lead to conditions such as anemia, headache, general weakness and fatigue, vomiting, abdominal pain, and constipation. Children are especially susceptible to lead poisoning, since they absorb lead more readily than adults. Even minor exposure can severely affect a child's development and lead to behavioral and learning problems. Early detection prevents long term exposure and permits earlier treatment. Although the current Center for Disease Control action threshold is 10 micrograms per deciliter (100 parts per billion), recent studies suggest there is no lower limit to Pb toxic effects, suggesting a value for very low reporting limits.
Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to screen large numbers of blood samples offers great flexibility in terms of speed of analysis, dynamic range and reporting limit when compared to more traditional methods such as Graphite Furnace Atomic Absorption. Furthermore, preparation of blood samples for ICP-MS requires only a simple dilution, minimizing the risk of contamination during the pre-analytical phase and speeding sample throughput.
The goal of this study was to maximize sample throughput for a basic toxic metals panel. We added uranium and manganese to the panel for reasons we will discuss. Using an Integrated Sample Introduction System (ISIS-DS) with the Agilent 7500cx ICP-MS, analysis time for a six element panel was only 100 sec (40 samples per hour), and the stability of the method was very good over an extended period of time. Modification of the panel composition, depending on diagnostic or research goals, is straight-forward. For example, for Pb only, we analyzed 90 specimens per hour for extended periods. We will present figures of merit for the method, including run times, method detection limits and verification against standard reference materials and previous study results.
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