Chromoionophore and method of determining potassium ions
Inventors
He, Huarui • Lin, Chao • Raje, Neeta • Liu, Chuseng
Assignees
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Publication Number
US-7960181-B2
Publication Date
2011-06-14
Expiration Date
Abstract
The invention relates to methods of determining potassium 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 potassium 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 chromoionophores for potassium ions (K+), where the chromoionophore comprises an ionophoric potassium-binding moiety and a chromophoric group. The chromophoric group has a UV/visible absorption that changes in response to K+ binding, and potassium ion concentration is determined by measuring an intensity change associated with one or more visible-region absorption maxima, including wavelengths of about 400 nm or greater.
The chromophoric moiety L is selected from —NO2 and Formula (II) and (III). The overall chromoionophore composition is defined by a general Formula (I), with substituent and ring-formation constraints governing the values of a, b, c, d, e, f and the relationships among R1–R10, including the formation of alkyl benzene rings, alkoxy benzene rings, a benzene ring, or a naphthalene ring based on the specified substituent groupings.
The invention also includes a method for determining potassium ion concentration in a sample by measuring an intensity of at least one absorption maximum of a potassium-sensitive chromoionophore solution before and after contacting the sample. The potassium concentration is derived based, in part, on the difference between the first and second intensities of the absorption maximum measured in the visible region. Example embodiments and structural scope include specific aromatic/heteroaromatic selections for Ar and additional narrowing options for the chromoionophore represented by Formula (IV)–(VII), and embodiments tied to sample types and sample pH thresholds.
Claims Coverage
The document includes two independent claims that cover a chromoionophore defined by a general Formula (I) with a specified chromophoric moiety L, and a method of determining potassium ion concentration by visible-region absorption measurements using such a chromoionophore. Together, the inventive features specify both the chromoionophore structure scope and the measurement scheme based on intensity differences at absorption maxima.
Chromoionophore defined by general Formula (I) with chromophoric moiety L
A chromoionophore of the general Formula (I) wherein a, b, c, d, e, f are selected according to the stated provisos; ring-formation constraints define how combinations of R1/R2, R3/R4, R5/R6, R7/R8, and R9/R10 with C1/C2, C3/C4, C5/C6, C7/C8, and C9/C10 form specified alkyl benzene rings, alkoxy benzene rings, a benzene ring, or a naphthalene ring; and L is a chromophoric moiety selected from —NO2, Formula (II) and (III) with Ar and W/R11 substituent and heteroatom requirements as stated.
Potassium ion concentration by visible-region absorption maximum intensity difference
A method of determining the concentration of potassium ions in a sample comprising measuring the intensity of at least one absorption maximum of a solution of a potassium-sensitive chromoionophore sensitive to potassium ions to obtain a first intensity, the absorption maximum having a wavelength in the visible region; contacting the chromoionophore solution with the sample whereby the first intensity changes; measuring the intensity of at least one absorption maximum to obtain a second intensity; and deriving the concentration of potassium ion based, in part, on the difference between the first and second intensities.
Overall, claim coverage is centered on a defined chromoionophore scaffold (general Formula (I) with chromophoric moiety L selected from —NO2 and Formula (II)/(III)) and a measurement method that derives potassium concentration from changes in visible-region absorption maximum intensity after contacting the sample.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
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