Chromoionophore and method of determining sodium ions
Inventors
He, Huarui • Lin, Chao • Raje, Neeta • Liu, Chusheng
Assignees
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Publication Number
US-7858383-B2
Publication Date
2010-12-28
Expiration Date
Abstract
The invention relates to methods of determining sodium ions in a sample, wherein the ions are contacted with a compound having chromophoric moiety and an ionophoric moiety, where the ionophoric moiety interacts with the sodium ions present in the sample, resulting in the chromophoric moiety changing its radiation absorption properties in the ultraviolet and visible regions of the spectrum. For example, a change in an intensity of an absorption maximum is measured and the ion concentration is determined accordingly.
Core Innovation
The invention relates to a sodium-ion colorimetric sensing concept based on a chromoionophore of Formula (I). The chromoionophore is sensitive to the presence of sodium ions in solution and includes r and s independently selected from 0, 1 or 2, with L as a chromophoric moiety selected from −NO2, Formula (II) and (III). Ar is an aromatic moiety or a heteroaromatic moiety containing heteroatoms selected from N, O, and S, and is substituted by one or more substituents selected from hydrogen, −NO2, −NO, −CN, alkyl, alkenyl, halogen, sulfonic acid (−SO3H), and substituted carboxyl or related groups defined through W and N(R1)3 and carbonyl/alkoxycarbonyl substituents.
The chromoionophore is defined with W as an alkylene and R1 as hydrogen or a straight chain or branched alkyl, with a proviso that when r is 1 and s is 0, then L is not [specified as incomplete in the provided claim excerpt]. In this arrangement, the chromoionophore is sodium-ion-sensitive in solution and is used for colorimetric sensing based on absorption-intensity changes.
The sensing mechanism is implemented by determining sodium ion concentration through intensity changes at at least one absorption maximum. A solution of the Formula (I) chromoionophore is measured to obtain a first intensity, the chromoionophore solution is contacted with the sample to obtain a second intensity after the first intensity changes, and the sodium ion concentration is derived based, in part, on the difference between the first and second intensities.
Claims Coverage
The document includes two independent claims: one directed to a specific chromoionophore chemical structure of Formula (I), and one directed to a method for determining sodium ion concentration using absorption maxima of a sodium-ion-sensitive chromoionophore. The inventive features are centered on the defined chromoionophore structural scope and the absorption-maximum intensity measurement workflow with derivation from intensity differences.
Formula (I) chromoionophore with chromophoric moiety L and substituted Ar
A chromoionophore of Formula (I) wherein r and s independently are selected from 0, 1 or 2; L is a chromophoric moiety selected from −NO2, Formula (II) and (III); Ar is an aromatic moiety or a heteroaromatic moiety containing heteroatoms selected from N, O, and S; Ar is substituted with one or more substituents selected from hydrogen, −NO2, −NO, −CN, alkyl, alkenyl, halogen, −SO3H, substituted carboxyl or related groups defined through W and N(R1)3, and carbonyl/alkoxycarbonyl substituents; W is an alkylene; and R1 is hydrogen or a straight chain or branched alkyl, with the proviso that when r is 1 and s is 0, then L is not [specified as incomplete in the provided claim excerpt].
Determining sodium ion concentration by deriving from intensity differences of absorption maxima in the visible region
A method of determining the concentration of sodium ions in a sample comprising measuring the intensity of at least one absorption maximum of a solution of a chromoionophore of Formula (I), obtaining a first intensity, contacting the solution with the sample to change the first intensity, measuring the intensity of at least one absorption maximum to obtain a second intensity, and deriving the concentration of sodium ion in the sample based, in part, on the difference between the first and second intensities; said at least one absorption maximum has a wavelength in the visible region.
Across the independent claims, the core coverage is the defined sodium-ion-sensitive chromoionophore (Formula (I) with L and substituted Ar constraints plus r/s variability and a proviso) and a sodium concentration determination method based on visible-region absorption-maximum intensity changes measured before and after contacting the chromoionophore solution with the sample.
Stated Advantages
Provides a method of determining the concentration of sodium ions in a sample using a sodium-ion-sensitive chromoionophore whose absorption maxima in the visible region change in intensity.
Documented Applications
Determining the concentration of sodium ions in a sample, including use with samples described as biological fluid samples.
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