Solid phase extraction method for detection of chloramphenicol in animal-derived foods (SilibaseTM C18)
First, the purpose of the experiment
In this study, solid phase extraction was used as a pretreatment method for samples, and LC-MS method was used as a detection method. The method can simplify the pretreatment process of the sample, save the use of organic solvents, and is easy to operate.
Second, the experimental target
Chloramphenicol (CAS: 56-75-7)
Third, the scope of application
The method is suitable for LC-MS/MS detection and confirmation of chloramphenicol in animal-derived foods.
Fourth, the reference standard
Recommended national standard "GB/T 22338-2008 Determination of chloramphenicol residues in animal-derived foods"
V. Experimental materials
Biocomma® SilibaseTM C18 Solid Phase Extraction Column 6mL/1000mg.
Sixth, experimental methods
1, sample extraction
A 5 g sample will be weighed to the nearest 0.01 g. Place 50 ml in a vortex cap centrifuge tube, add 5 ml of water, and mix rapidly on a vortex mixer for 1 min to completely dissolve the sample. Accurately add 15ml of ethyl acetate, shake it on the shaker for 10min, centrifuge at 3000r/min for 10min, accurately absorb 12ml of the upper layer of ethyl acetate and transfer it to a 15ml centrifuge tube, and then immerse it in a concentrated nitrogen blower at 45 °C. Add 5 ml of water to dissolve and purify.
2, SPE column purification
- Activation: C18 solid phase extraction cartridge was activated by using 5 mL of methanol and 5 mL of water in sequence.
- Purification: The extract was passed through a C18 solid phase extraction column. After the solution was completely discharged, the column was passed through 2 x 3 ml of water, and then the column was rinsed with 5 ml of acetonitrile + water, and all the leachate was discarded. It was evacuated by vacuum pump for 10 min.
3, elution
The extract was eluted with 6 ml of ethyl acetate. The eluate was collected in a 10 ml centrifuge tube, dried at 45 ° C with a nitrogen purge, and made up to 1 ml with acetonitrile + water (2:8, by volume) for LC-MS. /MS on the machine.
4, LC-MS conditions
Column: Venusil ASB C18 (2.1 × 150 mm, 5 μm, 100 Å);
Mass spectrometer: API 4000
Mobile phase: A: 0.1 mM ammonium acetate solution (0.1% formic acid) B: methanol solution;
Flow rate: 0.2mL/min
Column temperature: 40 ° C
Injection volume: 5ul
Ion source: electrospray (ESI), negative ion mode
Detection method: multiple reaction monitoring (MRM).
Table 1 mass spectrometer ion source parameters
Source/Gas | |
Collision Gas (CAD) | 6 |
Curtain Gas (CUR) | 30 |
Ion Source Gas 1 (GS 1) | 50 |
Ion Source Gas 2 (GS 2) | 50 |
Ion Spray Voltage(IS) | -4500 |
Temperature(TEM) | 550 |
Interface Heater(ihe) | On |
Table 2 Table of parent and daughter ion parameters of chloramphenicol and internal standard
| Substance name | Retention time (min) | Monitoring ion pair | DP | EP | CE | CXP |
Chloramphenicol | 4.90 | 320.9/151.9 | -60 | -10 | -25 | -12 |
320.9/256.9 | -60 | -10 | -25 | -12 | ||
Chloramphenicol-D5 | 4.90 | 326.1/157.0 | -60 | -10 | -25 | -12 |
Seven, the experimental results
1, 10ppb pork matrix chloramphenicol added recovery results
The average spiked recovery rate is above 90%, and the RSD value is less than 5 to meet the standard requirements.
Table 3 Pork matrix chloramphenicol added recovery results
name | 1(%) | 2(%) | 3 (%) | The average recovery rate(%) | RSD (%) |
Chloramphenicol | 98.31 | 96.28 | 90.61 | 95.07 | 4.20 |
2, blank sample added chloramphenicol residue chromatogram
Related applications
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