Multicomponent model parameterisation
AssigneeMalvern Panalytical Limited
InventorsSeyi Latunde-Dada, Oksana Iryna Leszczyszyn, Karl Hampton, Rachel Bott
Life of this patent
Estimating the term…
Abstract
A method of estimating a parameter for fitting a multi-component Taylorgram model to Taylorgram data g(t) is disclosed. The data comprises a multi-component Taylorgram peak or front at t=tr. The method comprises: evaluating a value of an integration or differential of the data; determining the parameter, based on an analytical expression that includes the value of the integral or differential of the data, the parameter corresponding with a physical property of a sample from which the Taylorgram data was obtained.
Claims15
A method of estimating a diffusion coefficient or hydrodynamic radius of a sample by:
- performing a Taylor dispersion analysis, wherein performing the Taylor dispersion analysis comprises:
- flowing a carrier solution through a capillary;
- injecting a sample fluid into the capillary to form a sample plug or a sample front;
- determining Taylorgram data by measuring absorbance over time at a detector as the sample plug or sample front flows past the detector;
- and
- using a computer to fit a multi-component Taylorgram model to the Taylorgram data g(t) obtained from the sample, the Taylorgram data comprising a multi-component Taylorgram peak or front at t=tr;
- the method comprising:
- evaluating a value of an integration or a differential of the data;
- determining the diffusion coefficient or hydrodynamic radius of a component of the multi-component Taylorgram model, based on an analytical expression that includes the value of the integral or differential of the data, the diffusion coefficient or hydrodynamic radius corresponding with a physical property of a component of the sample from which the Taylorgram data was obtained;
- determining a maximum value, w, of a differential of the data,
- d
-
-
- g
-
- (
- t
- )
- dt
- ,
- and a value t′ corresponding with the maximum value, w;
- and
- determining the diffusion coefficient or hydrodynamic radius from the values w, t′ and tr.
A method of estimating a diffusion coefficient or hydrodynamic radius of a sample by:
- performing a Taylor dispersion analysis, wherein performing the Taylor dispersion analysis comprises:
- flowing a carrier solution through a capillary;
- injecting a sample fluid into the capillary to form a sample plug or a sample front;
- determining Taylorgram data by measuring absorbance over time at a detector as the sample plug or sample front flows past the detector;
- and
- using a computer to fit a two-component Taylorgram model to the Taylorgram data g(t), the data being a Taylorgram obtained from the sample comprising a multi-component Taylorgram peak or front at t=tr, the method comprising:
- performing a least squares fit of a single component Taylorgram model to the data g(t);
- determining the diffusion coefficient or hydrodynamic radius by finding a root of a cubic equation, the cubic equation derived from:
- an analytical expression for the integrated residual squared error, R2, resulting from a fit of a one-component Taylorgram model to a two-component Taylorgram distribution;
- and a priori knowledge of the standard deviation, α, of a dominant Taylorgram component of the data g(t);
- and,
- wherein the two-component Taylorgram model is of the general form:
- g
- model
-
- (
- t
- )
- =
- ∑
- i
- =
- 1
- 2
-
- A
- i
- ·
- e
- -
- 0.5
- ·
- (
- t
- -
- t
- r
- σ
- i
- )
- 2
- ;
- and,
- the cubic equation is:
- a·s23+b·s2+c=0, where
- s
- 2
- =
- σ
- 2
- σ
- 2
- 2
- +
- σ
- s
- 2
- ;
- a
- =
- 2
-
- (
- A
- peak
-
- σ
- 1
- σ
- 1
- 2
- +
- σ
- s
- 2
- -
- A
- s
- )
- ;
- b
- =
- A
- s
- -
- 2
-
- A
- peak
- (
- σ
- 1
- σ
- 1
- 2
- +
- σ
- s
- 2
- )
- 3
- ;
- and
- c
- =
- A
- s
- (
- 2
-
- (
- σ
- 1
- σ
- 1
- 2
- +
- σ
- s
- 2
- )
- 3
- -
- σ
- 1
- σ
- 1
- 2
- +
- σ
- s
- 2
- )
- .
Dependencies are inferred from the claim text.