Lead assay

摘要

Process for metering lead in a sample of original water, in which is placed a sample of the water of which at least a substantial portion of the colloidal and organic material is passed in solution (sample of pretreated water), having: a first stage, starting from a sample of pretreated water with an adjusted pH, the lead is concentrated and the other parasitic ions are at least partially eliminated to obtain a sample of water that is concentrated with lead and substantially lacking in other parasitic ions (sample of lead-concentrated water); and a second stage in which, starting from the sample of lead-concentrated water, the sample of lead-concentrated water is mixed with a selective, lead-sensitive fluorescent probe whose fluorescence intensity/lead metering function is known; then, the thus produced water/fluorescent probe mixture is excited by the light, and the fluorescence intensity of the thus excited water/fluorescent probe mixture is collected optically; finally, starting from the thus detected fluorescence intensity, the lead metering of the sample to be metered is determined based on the fluorescence intensity/lead metering function.

主权项

1. Process for metering lead Pb2+ in a sample of water containing lead Pb2+, said process comprising the following successive stages:
providing the sample of water containing lead Pb2+; performing stage (A) of obtaining a lead-concentrated water sample with a lead concentration factor of at least 25, by concentrating the lead Pb2+ of said sample of water; and performing stage (B) with the following sequential steps: mixing water from the lead-concentrated water sample with a selective, lead-sensitive fluorescent probe with a known fluorescence intensity/lead metering function to produce a water/fluorescent probe mixture, exciting the thus-produced water/fluorescent probe mixture by light, and optically collecting a resulting fluorescence intensity of the thus-excited water/fluorescent probe mixture to determine a detected fluorescence intensity, and starting from the thus-detected fluorescence intensity, the lead metering of the sample to be metered is determined based on the fluorescence intensity/lead metering function, wherein stage (A) is performed as follows: a first sub-stage (A1) of passing said sample of water containing lead Pb2+ as received in the providing step, over a selective adsorbent that does not fix other parasitic ions to thereby adsorb the lead Pb2+ from said sample of water on the selective adsorbent, wherein said selective adsorbent is functionalized silica balls, and a second sub-stage (A2) of initiating a desorption of the lead Pb2+ with an eluent to thereby obtain the lead-concentrated water sample that is concentrated with the lead Pb2+ and that is substantially lacking in other parasitic ions.