Patent ID: 7813882

Claim:
A method to determine the average molecular properties of a solution of molecules in a solvent, said average molecular properties being the weight average molar mass M, the mean square radius <r g 2 >, the 2 nd virial coefficient A 2 , and the 3 rd virial coefficient A 3 , comprising the steps of A. providing a reservoir of said solvent; B. providing a reservoir of said solution; C. preparing from said reservoirs a series of n dilutions D m (m=1,n) of said solution, using a dilution means, by said solvent; D. providing sampling means by which said dilutions D m (m=1,n) are sequentially injected and made to flow through serially a. a light scattering detection means that collects light scattered at a plurality of q angles θ k (k=1,q) at each incremental injection volume Δv i of said dilution D m (m=1,n); b. a concentration detection means that measures the corresponding molecular concentrations c mi (m=1,n) at each incremental injection volume Δv i of said dilution D m (m=1,n); E. generating from the measured scattered light intensities and the corresponding concentration c mi at each flow volumetric incremental interval Δv i the associated excess Rayleigh ratios R*(θ k ,c mi ); F. calculating the n concentration sums C m = ∑ i ⁢ c mi ⁢ Δ ⁢ ⁢ v i corresponding to each said dilution D m , where m=1 to n, from said collected molecular concentration values, c mi , over the entire elution of each said dilution m; G. calculating the 3qn excess Rayleigh ratios sums, R 1 , m ⁢ ⁢ i = ∑ i ⁢ [ R * ⁡ ( θ k , c m ⁢ ⁢ i ) ] ⁢ Δ ⁢ ⁢ v i , ( k = 1 , q ; m = 1 , n ) , R 2 , mk = ∑ i ⁢ [ R * ( θ k , c m ⁢ ⁢ i ) ] 2 ⁢ Δ ⁢ ⁢ v i , R 3 , mk = ∑ i ⁢ [ R * ⁡ ( θ k , c m ⁢ ⁢ i ) ] 3 ⁢ Δ ⁢ ⁢ v i corresponding to said n dilutions, from said generated excess Rayleigh ratios R*(θ k , c mi ); H. extracting said average molecular properties of said solution of molecules from said 3qn excess Rayleigh ratios sums by fitting the collected concentration values and generated excess Rayleigh ratio values with an appropriate equation relating said concentration sums and said excess Rayleigh ratio sums with variables representative of said average molecular properties of said solution of molecules as the parameters of the fit.