1. Experimental conditions
Cometro (US Connaught) high performance liquid chromatography system;
Cometro (US Connaught) 6000 LDI Pump;
Softa (Sofoda USA) ELSD (evaporative light scattering detector), DT-70 ℃, SC-30 ℃;
Scienhome (Tianjin Chenhang) Kromasil NH2 column;
Mobile phase: acetonitrile-water = 70-30;
Flow rate: 1.0ml / min;
Lactose standard concentration is 0.5mg / mL, 1mg / mL, 1.5mg / mL;
Sample configuration of whey powder: Take 0.1g of powder and put it in a 100mL volumetric flask, and bring the volume to the mark with water.
The injection volume is 20ul.
Second, the experimental results
Sample one:
Detector 1 Results
Retention Time
Area
Theoretical plates (USP)
Resolution (USP)
2.698
104649
1083
0.00000
16.797
3671699
5914
23.46733
Sample two:
Detector 1 Results
Retention Time
Area
Theoretical plates (USP)
Resolution (USP)
2.695
149923
792
0.00000
16.871
3700293
5739
22.25627
Sample three:
Detector 1 Results
Retention Time
Area
Theoretical plates (USP)
Resolution (USP)
2.688
133156
845
0.00000
16.821
3733804
5535
22.18048
Lactose standard (inject three times at different concentrations, and reinject 2 times at a concentration of 1 mg / ml for reproducibility)
Relationship between concentration and peak area:
concentration
Peak area
Unknown (Sample 1)
3671699
Unknown (Sample 2)
3700293
Unknown (sample three)
3733804
Standard product 0.5mg / mL
2288817
Standard product 1.0mg / mL
4865288/4844636/4797327 RSD = 0.72%
Standard product 1.5mg / mL
7750119
Take lg concentration as abscissa and lg peak area as ordinate
Bring the concentration of the sample into the three sample concentrations that can be calculated by the equation and the mass percentage relative to the powder:
Concentration mg / mL
Mass percentage
Sample one
0.769619
76.96%
Sample two
0.775031
77.50%
Sample three
0.782605
78.26%
Three, discussion of results
It can be seen from the figure that the chromatographic column has a good peak shape for the sample, high column efficiency, and good reproducibility of the Softa ELSD (evaporative light scattering detector) (RSD = 0.72%) with a good linear relationship R2 = 0.999).
High Efficiency Filter,Hepa Air Filter V Style,99.9% Hepa Filtration,Synthetic Fiber Efficiency Filter
Ningbo Ifilter Purification Equipment CO.,Ltd. , https://www.nbifiltor.com