Non-azo 1,8-naphthalimide dyes for the detection and quantitation of a paramagnetic metal cation in a non-aqueous medium

A method for determining the presence or amount of a paramagnetic metal cation in a non-aqueous solution, comprising the steps of:

• mixing a non-azo 1,8-naphthalimide dye with the paramagnetic metal cation in the non-aqueous solution to give a mixture;
• irradiating the mixture with a fluorescent light sufficient to cause the mixture to emit a detectable fluorescent emission spectrum;
• detecting the fluorescent emission spectrum of the mixture;
• and,
• comparing the detected fluorescent emission spectrum with standard fluorescent emission spectra generated by reacting the non-azo 1,8-naphthalimide dye with different known amounts of the paramagnetic metal cations, wherein differences between the fluorescent emission spectra compared are dependent upon the presence or amount of the paramagnetic metal cation present in the mixture.

A method for distinguishing an ion of an f-block element from an ion of a d-block element in a non-aqueous medium, comprising:

• mixing a non-azo 1,8-naphthalimide dye with a non-aqueous solution containing the ion of the f-block or d-block element to give a mixture;
• irradiating the mixture with a fluorescent light sufficient to cause the mixture to emit a detectable fluorescent emission spectrum;
• detecting a fluorescent emission spectrum of the mixture;
• and
• monitoring differences in the detected fluorescent emission spectrum of the mixture, as compared to standard fluorescent emission spectra generated by reacting the non-azo 1,8-naphthalimide dye with different known amounts of the ion of the f-block or d-block element, wherein the detection of quenching in the spectra indicates the presence of the ion of the f-block element.