Introduction

On April 2002, researchers from Swedish National FDA and University of Stockholm first reported that acrylamide have been detected on many oil-fried and baked starchy foods, such as French fries, potato chips and so on, and the contents of acrylamide exceeded more than 500 times of the maximum permitted level of acrylamide in drinking water. The similar results have been reported by researchers from Norway, United Kingdom, Swiss and USA. In 2010 a joint Food and Agriculture Organization and World Health Organization expert committee determined there was evidence that acrylamide could cause cancer in laboratory animals. Although there is no sufficient evidence that acrylamide intake through food has a significant relationship with the occurrence of any type of cancer in human, the investigation results on professionals who contact acrylamide frequently and on people who contact acrylamide occasionally showed that acrylamide has neurotoxicity, and agreed that we should reduce our exposure.

Materials

Reagents
n-Hexane (HPLC grade, 4L/bottle, P/N: AH216), Watsons Water, Acrylamide (1000ppm in MeOH).
Instrumentals and materials
Agilent 1200, N2 blow-dry machine, ultrasound, high-speed centrifuge PTFE syringe filter 0.22 μm, 50 ml centrifuge tube, 12-position vacuum manifold SPE.

Methods

Sample preparation
Weigh 2 grams potato chips and grounded into very fine powder, then put into a 50 ml centrifuge tube. Add 30 ml ultra-pure water, vortex oscillated and Ultrasonic vibrated for 10 min, then centrifuged at 6000 rpm. Collect 15 ml supernatant solution and put into a new 50 ml centrifuge tube mixed with 5 ml n-hexane, followed by vortex oscillated for 1 min. Then the mixture is centrifuged at 6000 rpm for 10 min. Pipette out the upper layer of n-hexane. Repeat the centrifuge and n-hexane extraction steps once. The resultant 15 ml sample solution is ready for next step.
SPE method
SPE cartridge: Cleanert ACA 500 mg / 12 mL (P/N: ACA50012); Conditioning: 5 mL MeOH and 5 mL water (Vaccum filtration); Sample Loading: 15 mL sample solution from above step; Washing: 5 mL Watsons Water; Vacuum filtration 30 min, dried the column ; Elution: 3 mL MeOH (Vacuum filtration, collect); At 40 °, N2 blow dry to 100-200 μL, then add Watsons Water to dilute to 2 mL, filtered by 0.22 μm PTFE syringe filter, then sample is ready for HPLC.
HPLC method
HPLC Column: Unisol C18, 4.6x250 mm, 5.0 μm, 100 Å (P/N: VA952505-0 ); Mobile phase: Watsons Water; Flow rate: 1.0 mL/min; Injection sample: 20 μL; UV Wavelength: 210 nm; Column temperature: RT.

Method validation

Standard calibration curve
Dilute the standard samples to the following concentration: 1, 2, 5, 10, 20, 50 μg/ml. A calibration curve is generated according to the peak areas at different concentration.
Sample analysis using HPLC
Analyse the samples from above sample preparation and quantitated with external standards.
Formulation
Acrylamide contents calculated by the following formula:

Results and conclusions