Determination of Sucralose in Soy Sauce using HPLC-ELSD following the Chinese National Standard (GB) Method

Introduction

The most frequently used synthetic sweeteners are: saccharin, cyclamate, aspartame, and sucralose (E955), and this application illustrate the analysis of sucralose from soy sauce following the current Chinese national standard method.

Quantitation of sucralose was carried out through ELSD detection after chromatographic separation on a Discovery® HS C18 HPLC column. Sample preparation was performed on Supelclean™ SELECT HLB solid phase extraction (SPE) cartridges. Satisfying chromatographic results could be obtained, and it was possible to construct an exponentially fitted calibration curve with adequate regression, providing Limit of Detection (LOD) and a Limit of Quantitation (LOQ) meeting testing requirements

Sucralose

 

Experimental Conditions
column: Discovery®  C18 15cm X 4.6 mm (5um) (504955)
mobile phase: [A] water; [B] Acetonitrile; (89 : 11, A : B)
flow rate: 1.0 mL/min
detector: ELSD
injection: 20 µL
column temp: 35 °C
sample: Standard solution: Dissolve appropriate amount of Sucralose in water to obtain a 200 µg/mL of solution . sample: weigh 2g of soy sauce into a 50-mL centrifuge tube, add into 1.0 g neutral aluminum oxide , add into 3 mL water, vortex for 3 minutes, add into 15 mL methanol, shake for 30 seconds, sonicated for 20 minutes, centrifuge at  3000 r/min for 10minutes. Transfer the supernatant to 50-mL centrifuge. Add  5.0 mL of 75% methanol aqueous solution to precipitate, stir well with glass rod, vortex for 30 seconds, centrifuge at 3000 r/m for 10 minutes. repeat the extraction procedure twice. pool the above supernatant to one 150-mL separating funnel. add into 30 ml hexane, shake for 2 minutes, standing for separating for 2o minutes, transfer the lower aqueous solution to 50-mL evaporating dish to evaporate until around 1 mL of solution left. add into 9 mL water to dissolve and transfer the solution to a 15-mL centrifuge, sonicate for 5 minutes at 3000 r/min for 10 minutes.  the supernatant solution is ready for next step of SPE clean-up.

 

SPE sample preparation
SPE cartridge Supelclean™ SELECT HLB SPE, 200mg / 6mL (54183-U)
conditioning 4 mL methanol, then 4 mL water
sample addition 10 mL sample solution mentioned below
washing maintain the dropping speed at 1 drop/ sec, add 1 mL water into the SPE cartridge when liquid surface is 2 cm higher than the sorbent
elution 3 mL methanol at a flow rate of 1 drop / sec
elution post-treatment evaporate to dryness in an evaporating dish, reconstitute in 2 mL of mobile phase, filter with 0.45 µm filter membrane

 

Specificity and Repeatability

1. Specificity: Inject Standard Solution and determine the retention time and monitor the peak purity

No. Name RT Plates (USP) Tailing Factor Peak Purity
1 Sucralose 8.8 19417 1.1 1.0000


2. Standard Repeatability (Sucralose, 200 ppm)
 

Measurements  Mean Area
STD 1 323.2
STD 2 329.1
STD 3 329.7
STD 4 328.3
STD 5 323.7
Mean 326.8
Standard Deviation 3.10
RSD (%) 0.9

 

3. Power exponent
 

Concentration (μg/mL) Mean Area
20.0 5.2
50.0 21.8
100.0 86.2
200.0 323
400.0 1089

 

Power exponent equation of sucralose

SPE recovery of sucralose
(Soy Samples spiked at 0.05g/kg)

SPE Recovery
 

Sample No. Recovery (%)
Sample 1 104
Sample 2 115
Sample 3 105
Average 108
RSD (%) 5.7

 

Materials