HPLC for Food Analysis phần 3 ppt

17

Sample preparation Sample preparation

was done according to

reference9

Column 250 x 4.6 mm

Spherisorb ODS-2, 5 µm

Mobile phase A = sodium acetate

buffer, 0.02 M, pH = 4.8

B = ACN/water (60:40)

Gradient start with 8 % B

at 5 min 8 % B

at 7 min 20 % B

at 14 min 23 % B

at 16 min 33 % B

at 19 min 40 % B

at 21 min 50 % B

at 26 min 60 % B

at 30 min 80 % B

at 33 min 90 % B

at 43 min 90 % B

at 55 min 8 % B

Flow rate 1.5 ml/min

Injection volume 20 µl

Detector UV-DAD

detection wavelengths

275/80 nm, 315/80 nm,

and 360/80 nm,

reference wavelength

500/100 nm

9. H. Malisch, et al.,“Determination of residues of chemotherapeutic

and antiparasitic drugs in food stuffs of anomaly origin with HPLC and

UV-Vis diode-array detection”, J. Liq. Chromatogr., 1988, 11 (13),

2801–2827.14.

10. EC Guideline 86/428 EWG 1985.

Chromatographic conditions

The HPLC method presented here for the analysis of

residues of drugs in eggs, milk, and meat is based on

reversed-phase chromatography and multisignal UV-visible

diode-array detection (UV-DAD). UV spectra were

evaluated as an additional identification tool.

Figure 11

Analysis of residues in an egg sample. Identification through

spectra comparison

HPLC method performance

Limit of detection 0.001–0.05 mg/kg

Repeatability

of RT over 10 runs < 0.12 %

of areas over 10 runs < 1.5 %

80

40

0

250 300 350 400

Pyrazon

t = 9 min

match 998

R

offset

0

10

20

10 20 30

Egg sample

Standard

Time [min]

1

2

3

4

5

6,7

8

9

10

11

mAU

1 metronidazol

2 meticlorpindol

3 sulfapyridine

4 furazolidone

5 pyrazon

6 ipronidazol

7 chloramphenicol

8 N-acetyl metabolite of 3

9 3-ethopabat

10 benzothiazuron

11 nicarbazin

80

40

0

250 300 350 400

Sulfapyridine

t = 12.2 min

match 997

R

offset

Wavelength [nm] Wavelength [nm]

Scaled

Scaled