Determination of Phthalates Plasticizing in Food

1. Application Range

It is suitable for the determination of oil phthalate compounds (rapeseed oil is used as sample matrix in this experiment).

Reference: SN/T 3147-2017 Determination of Phthalate Estates in Exported Foods

2. Extraction Steps

1) take 5 g samples in glass tube, add 2 mL acetonitrile saturated n-hexane, mix with vortex , then add 4 n-hexane saturated acetonitrile. Mix by vortex, ultrasound for 10 min, centrifuge for 5 min (3000r/ min), carefully transfer the lower layer solution to another glass tube; Add 4 n-hexane saturated acetonitrile, repeat extraction once and combine two extracts.

2) Put extract in 40℃ water bath to dry, accurately add 5 mL acetonitrile and mix by vortex. Add it in Welchrom®QuEChERS purification tube (P/N：00533-20020), mix by vortex, centrifuge for 5 min (3000r/) and take the supernatant to be tested.

3. Chromatographic Conditions

 3.1 GC Conditions

 Column: WM-5MS,30m*0.25mm*0.25μm

 Injection inlet temperature: 260℃

 Temperature program: initial column temperature 60℃, maintain 1 min; rise at 20℃/ min to 220℃, maintain 1 min; and then rise at 5/ min to 250, maintain 1 min; rise at 20℃/ min to 290℃, maintain 7.5 min.

 Carrier gas: high-purity helium (purity >99.999%)

 Injection way: splitless injection

 Injection volume: 1μL

3.2 MS Conditions

Ionizing method: electron bombardment ionization source (EI)

Ionizing energy :70 Ev

Transmission line temperature :280℃

Ion source temperature :230℃

(b) Monitoring: ion scanning (SIM)

Solvent delay: 7.5 min

4. Chromatogram or Result of Spike Recovery

Fig 1. Chromatogram of 0.125μg/mL mixed standards phthalate esters 

Table 1 Related Peak Information

No.	Product	Retention	Width	Area
1	DMP	7.995	0.026	231015
2	DEP	8.84	0.022	215986
3	DIBP	10.624	0.026	331212
4	DBP	11.384	0.028	240580
5	DMEP	11.73	0.029	80356
6	BMPP	12.442	0.055	144812
7	DEEP	12.807	0.034	65897
8	DPP	13.176	0.032	149986
9	DHXP	15.321	0.051	97533
10	BBP	15.498	0.038	75616
11	DBEP	16.971	0.038	20408
12	DCHP	17.669	0.035	61322
13	DEHP	17.833	0.033	51514
14	DPhP	17.982	0.033	53156
15	DNP	18.83	0.024	16379
16	DNOP	19.435	0.028	38063

Fig 2. Chromatogram of blank solvent  

Fig 3. Chromatogram of purified rapeseed oil samples

Fig 4. Chromatogram of purified rapeseed oil samples at 0.05mg/kg

Table 2. Recovery rate of spiked samples

No.	Name	Width	Area
1	DMP	91.08%	4.33%
2	DEP	92.83%	0.24%
3	DIBP	64.94%	0.85%
4	DBP	84.56%	2.40%
5	DMEP	98.81%	0.47%
6	BMPP	94.82%	4.31%
7	DEEP	111.22%	4.07%
8	DPP	93.01%	0.12%
9	DHXP	83.75%	0.11%
10	BBP	133.48%	5.74%
11	DBEP	138.31%	1.07%
12	DCHP	87.88%	0.42%
13	DEHP	75.59%	4.82%
14	DPhP	109.14%	1.41%
15	DNP	72.99%	3.40%
16	DNOP	68.25%	0.64%

5. Ordering Information of Related Products

P/N	Name	Specification
00533-20020	Purification tube	Welchrom® QuEChERS Purification tube-2ml，AOAC method，150mg MgSO4，50mg PSA，50mg C18E，used in fat and wax fruits and vegetables，100/pk
03904-22001	GC column	WM-5MS, 30m*0.25mm*0.25μm

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