to hydrocortisone For example -Instrumax CAD Performance inspection

1. Experiment purpose:hydrocortisone-Inspection Instrumax CAD Performance
2. Experimental conditions:
   1. Instruments: INSTRUMAX Charged Aerosol Detector (CAD)(CADetector a1)

INSTRUMAX Nitrogen Generator g15)

Agilent liquid chromatograph(HPLC-1200)

Pipette (Finnpipette F1 20-200μL)

• 1. Column: InfinityLab Poroshell 120 EC-C18 3.0*100mm 2.7μm
  2. Reagents: distilled water (Watson's), acetonitrile (Merck,HPLC level)
  3. Sample: hydrocortisone (5mL:25mg)
  4. Mobile phase: acetonitrile: water =35:65

1, experimental process

3.1 Experimental conditions

Mobile phase: acetonitrile: water =35:65

Column: InfinityLab Poroshell 120 EC-C18 3.0*100mm 2.7μm

Column temperature:35℃

Flow rate:0.4mL/min

Diluent: acetonitrile: water =50:50

CAD Conditions

Drift tube temperature:40℃ Atomized air flow:3L/min

Charging airflow:1L/min Charging current:1μA

Gain：0.05 RF：2.0

Sample configuration process

hydrocortisone(5mL:25mg) mother liquor concentration is 5mg/mL, gradually dilute with diluent to obtain 3mg/mL,2mg/mL,1mg/mL,500μg/mL,400μg/mL,300μg/mL,200μg/mL,100μg/mL,1μg/mL,0.01μg/mL equal concentration.

3.2 Experimental results

3.2.1 Baseline noise and baseline drift

3.2.2 Minimum detection concentration

Sample:0.01μg/mL hydrocortisone, injection 10μL

Refer to the following calculation formula to calculate the minimum detection concentration:

3.2.3 linear range

Sample:100μg/mL,200μg/mL,300μg/mL,400μg/mL,500μg/mL;

1mg/mL，2mg/mL，3mg/mL， 5mg/mL

Test procedure:

in turn 100μg/mL,200μg/mL,300μg/mL,400μg/mL,500μg/mL Sample injection liquid chromatograph, make a standard curve based on concentration and corresponding response.

find on the curve hydrocortisone The concentration is greater than 500μg/mL The reading at each point is compared with the measured value at each corresponding concentration point. The magnitude difference is 5%The concentration when is used as the upper limit of detection C_H, according to the obtained minimum detection concentration, it is the detection lower limit C_LValue, C_H/C_LRatios are in the linear range.

Calculate the measured sample concentration according to the standard curve

From this we can get C_Hfor 2.00×10^-3 g/mL，C_Lfor 9.17×10^-10g/mL, linear range=C_H/C_L

3.2.4 Overall machine performance (qualitative, quantitative repeatability)

Sample:10μg/mL,100μg/mL hydrocortisone Sample, each injection 5μL

Test procedure: After the baseline is stable, inject a certain volume into the system to obtain glucose Standard solution, continuous measurement 6 times, record the retention time and peak area of the chromatogram, and calculate the relative standard deviation RSD₆。

Test results:

2, summary and discussion

Summary of results

Discussion of results:It can be seen from the noise drift, minimum detection concentration, linear range, repeatability and other results that Instrumax Charged Aerosol Detector (CAD) High sensitivity, wide linear range, good repeatability and good overall performance.

3, References

GB/T 26792-2019 liquid chromatograph

JJG 705-2014 high-performance liquid chromatograph