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As I'm sure you've heard in the comments, this is no easy task. However, the easiest and maybe fastest (although possibly not the cheapest) way of testing for this mystery contaminant is just a couple of wide-range tests. What I would do: A wide-spectrum light spectroscopy test (UV through IR) An NMR Spectroscopy test. Compare both results to results from ...

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Making the solution in a single step is inaccurate up to impossible. Try to find a crystal of lead nitrate with the mass close enough to $\pu{1 mg}$ Try to weight up $\pu{1 mg}$ on scales with good enough accuracy. Try to make such $\pu{1 ppm}$ solution stable enough. The usual thing is to create a concentrated stock solution ( e.g $\pu{1000 ppm}$ and ...

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Russian interstate standard GOST 18293-72 "Drinking water. Methods for determination of lead, zinc and silver content" (PDF in Russian) suggests to use sulfarsazene (plumbone), which forms orange-yellow complex with lead(II). Reported method sensitivity (spectrophotometry): $\pu{0.5 μg L-1}.$ A brief review in English [1, p. 315]: To determine lead in ...

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Another possibility is the grease spot photometer (aka Bunsen photometer) German Wiki page. This can be homemade, you need a piece of paper, some wax or oil, two light sources, a meter stick and for the measurement of solutions also some e.g. cardboard to shield unwanted light. Also the darker the room, the better. The underlying idea is that light ...

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It is still possible to measure light absorbances of a colored solution without any photometer, simply by comparison. First you prepare a reference solution with maybe 10 ppm Pb and an excess of a colorless reagent making a colored compound or complex with Pb. You prepare a series of 10 test tubes. You add 1 mL of this reference solution in the first test ...

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Perhaps you can add H2S to create PbS (as a starting step). Then, based on an extract from Wikipedia on Lead Sulfide: Although of little commercial value, PbS is one of the oldest and most common detection element materials in various infrared detectors.[12] As an infrared detector, PbS functions as a photon detector, responding directly to the photons of ...

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Sorry to tell you a bad news. Classical methods, like titrimetry or gravimetry do not work very well at low concentrations. Failure would be a strong word. The beauty of EDTA is that it forms 1:1 complex with most metals. Pb is not an exception. If your lead solution is 0.000001 M, your EDTA solution should be 0.000001 M. Such concentrations are never ...

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