A method of measuring the concentration of metal ions in a sample comprising the steps of: providing a sample comprising a nonpolar, liquid hydrocarbon, suspected of containing a metal ion; adding a dye such as a spirobenzopyran dye or bathocuproine and a reducing agent to the sample; wherein the dye forms a complex with the metal ion; wherein the complex has a spectral shift in light absorbance relative to the dye; observing the spectral shift; and calculating the concentration of the metal ion in the sample., wherein the observing step comprises the step of measuring the absorbance spectrum of the nonpolar, liquid hydrocarbon after the adding step and one or more steps selected from the group consisting of measuring the absorbance spectrum of the nonpolar, liquid hydrocarbon before the adding step, measuring the absorbance spectrum of the spirobenzopyran dye, measuring the absorbance spectrum of the complex, and measuring the absorbance spectrum of a composition known to be free of the metal ion.adding bathocuproine and a reducing agent to the nonpolar, liquid hydrocarbon to create a spectral shift in light absorbance caused by complexation of the bathocuproine to the metal ion in the nonpolar, liquid hydrocarbon;, wherein the observing step comprises the step of measuring the absorbance spectrum of the nonpolar, liquid hydrocarbon after the adding step and one or more steps selected from the group consisting of measuring the absorbance spectrum of the nonpolar, liquid hydrocarbon before the adding step, measuring the absorbance spectrum of the bathocuproine dye, measuring the absorbance spectrum of the complex, and measuring the absorbance spectrum of a composition known to be free of the metal ion. Field of the Invention The invention relates generally to spectrophotometric methods of measuring trace quantities of metals in jet fuel. Description of the Prior Art It has been well established that trace quantities of certain metals will promote autoxidation of organic compounds in the presence of oxygen.While it has been observed that iron, zinc, and lead can promote the oxidative degradation of hydrocarbon fuels, copper and its compounds have been shown to be one of the most active and available oxidation initiator instability promoters.In jet fuel, the possible presence of sulfur containing ligands or other ligands that favor the formation of tetrahedral copper coordination complexes could stabilize the Cu(I) oxidation state, making the Cu(I) concentration in jet fuel a quantifiable fraction of the total copper content.The sample may contain a metal deactivating additive (MDA).Although it is generally believed that Cu(II) is the primary culprit in the oxidation degradation of hydrocarbon fuels, Cu(I) can also play an important role in this process.While Cu(I) is recognized as being very unstable in aqueous solution, K=[Cu(II)]/[Cu(I)], the relative stability of Cu(I)/Cu(II) depends very strongly on the type of anions or ligands present in solution.The determination of copper in fuel to this level is nontrivial.Graphite furnace-atomic absorption spectroscopy analysis is currently the only method available to reliably quantify copper in fuel at these low levels.
While there are numerous metallochromic spectrophotometric methods for quantitating copper levels in aqueous media, there have been no reports to date dealing with the direct application of these dyes to fuels.
Their biggest break was an opening slot for Thin Lizzy in 1984, and was also one of their last shows until they reunited in 2002. The vocals are almost folky and sweet with a great deal of conviction, and the guitars are remniscient of early Iron Maiden and Cirith Ungol with possibly King Crimson and other 70's prog & rock.
Every member was talented and the lyrics show the intelligence of the band with diatribes of politics, religion, morality and psychological struggles.
This is one of my top 5, maybe even top 2 favorite NWOBHM records ever.
Legend hailed from a tiny island from the UK which they rarely left, and self pressed only 2,000 copies of this record which have all sold out, so needless to say it's a very rare piece of music, and like Detente's debut it often goes for prices reaching 0 or more. the production (self produced, of course) is a warm almost AM radio sounding affair, albeit clear and concise, and really sets it apart from the other metal of the time which had that big heavy bombastic sound.