Evaluation of different food matrices via a dihydropteroate synthase-based biosensor for the screening of sulfonamide residues

Figures & data

Figure 1. (A) Comparison of OD_max using PBS and Tris-HCl containing 5 mM MgCl₂ as extraction buffers for chicken. (B) Matrix effect of chicken with different dilution ratios using PBS containing 5 mM MgCl₂ as an extraction buffer. (C) Matrix effect of chicken using Tris-HCl containing 0.2% milk and 0.2% casein as extraction buffers. (D) Matrix effect of chicken extracts with different concentrations of skim milk. (E) Matrix effect of chicken extracts with different concentrations of NaCl. (F) Matrix effect of chicken extracts with different concentrations of BSA. (G) Standard curves of SMZ in chicken after 1/5 dilution in PBS containing 5 mM MgCl₂ and 0.1% BSA. (H) Comparison of different extraction methods for chicken in terms of OD_max and IC₅₀ values.

Table 1. Recovery studies from chicken, pork, eggs and honey with five SAs at three levels by DHPS-based biosensor.

Samples	SAs	Spiked concentration (μg kg^−1)	Intra-assay (n = 4)						Inter-assay (n = 3)
			Recovery (%)	CV (%)	Recovery (%)	CV (%)	Recovery (%)	CV (%)	Recovery (%)	CV (%)
Chicken	SMZ	30	78.8	17.8	88.2	15.3	87.2	15.6	84.7	6.1
		50	64.4	3.0	73.2	3.5	84.1	18.9	73.9	13.3
		100	62.5	2.4	60.3	16.3	83.7	13.5	68.8	18.8
	SDM	30	90.0	17.1	69.9	3.6	85.9	19.5	81.9	9.8
		50	79.4	7.2	66.7	14.8	71.2	2.9	72.4	8.9
		100	88.8	8.1	62.3	3.2	62.2	11.1	71.1	21.6
	SQX	30	62.5	4.0	80.7	12.7	69.4	13.5	70.9	12.9
		50	81.0	7.6	89.3	4.5	107.3	4.7	92.5	14.5
		100	77.8	2.0	72.4	6.4	68.8	9.2	73.0	6.2
	SMM	30	88.3	19.5	67.0	11.7	74.5	9.1	76.6	14.1
		50	102.6	13.7	89.3	5.9	89.9	14.7	94	8.0
		100	90.4	6.4	98.8	4.7	76.7	16.1	88.6	12.6
	SMX	30	69.7	11.9	71.2	8.7	81.7	10.8	74.2	8.8
		50	76.9	12.7	78.2	19.8	69.9	20.7	75.0	6.0
		100	96.2	9.9	85.2	11.1	76.7	11.4	86.0	11.3
Pork	SMZ	30	84.2	16.5	70.1	8.7	69.2	7.5	74.5	11.2
		50	72.3	7.6	68.0	2.7	70.7	7.1	70.3	3.1
		100	61.0	2.7	73.7	3.1	80.4	3.2	71.7	13.8
	SDM	30	91.3	5.4	83.9	3.1	75.2	19.8	83.5	9.6
		50	66.0	4.0	67.2	4.3	62.5	6.9	65.2	3.8
		100	77.1	6.8	71.7	5.9	78.3	2.8	75.7	4.7
	SQX	30	74.4	19.8	81.0	18.4	84.5	8.2	80.0	6.4
		50	83.4	4.7	110.5	1.5	81.4	1.2	91.8	17.7
		100	60.8	13.5	60.8	2.1	67.6	12.6	63.1	6.2
	SMM	30	104.6	12.3	96.8	8.8	74.8	11.1	92.1	16.8
		50	76.1	5.6	87.7	13.7	79.2	17.1	81.0	7.4
		100	75.8	10.1	87.8	2.2	97.3	12.3	86.9	12.4
	SMX	30	74.7	5.9	94.1	5.3	84.3	12.4	84.4	11.5
		50	84.5	12.8	95.3	10.0	82.5	4.4	87.4	7.9
		100	90.7	1.7	83.0	14.1	104.5	6.1	92.7	11.8
Eggs	SMZ	45	121.7	10.8	118.2	18.1	102.5	12.8	114.1	8.9
		90	108.4	16.9	118.4	6.7	94.7	13.4	107.1	11.1
		135	104.7	21.7	107	14.4	119.4	6.8	110.4	7.1
	SDM	45	99.0	2.7	121.8	5.5	101.3	11.0	107.4	11.7
		90	107.2	15.3	99.9	6.6	120.2	7.3	109.1	9.4
		135	117.0	9.2	123.0	17.3	115.1	2.7	118.4	3.5
	SQX	45	122.3	6.8	110.5	14.1	128.6	17.7	120.5	7.7
		90	120.1	13.6	97.0	4.0	114.2	13	110.4	10.9
		135	115.2	22.9	114.7	18.0	124.1	13.7	118.0	4.5
	SMM	45	113.7	11.1	115.7	8.6	91.9	13.1	107.1	12.3
		90	105.1	4.1	89.7	2.8	121.6	8.6	105.5	15.1
		135	96.5	17.8	101.1	14.7	111.7	11.8	103.1	7.6
	SMX	45	93.3	3.5	83.9	18.8	100.1	9.4	92.4	8.8
		90	88.8	2.7	90.3	3.4	100.8	2.2	93.3	7.0
		135	83.0	22.3	92.1	5.8	91.9	13.3	89.0	5.8
Honey	SMZ	5	58.6	9.8	59.2	11.0	53.7	5.4	57.2	5.3
		10	59.4	21.3	63.7	5.6	55.6	5.2	59.6	6.8
		15	56.4	18.4	49.4	6.7	47.7	2.4	51.1	9.0
	SDM	5	93.3	2.5	76.3	19.1	68.7	16.4	79.4	15.8
		10	74.8	4.8	57.2	3.2	53.1	1.8	61.7	18.7
		15	84.0	0.6	59.5	4.2	54.8	4.2	66.1	23.8
	SQX	5	135.1	4.7	125.7	4.9	123.1	4.1	139.3	18.6
		10	119.9	8.2	84.8	1.9	115.6	1.5	106.8	17.9
		15	113.2	5.0	101.6	4.4	110.8	10.8	108.5	5.6
	SMM	5	56.1	19.7	59	25.6	69.4	10.2	61.5	11.4
		10	65.9	13.8	79.4	10.9	60.6	22.7	68.6	14.1
		15	57.7	18.1	79.3	6.2	52.8	5.0	63.3	22.3
	SMX	5	73.1	3.0	69.4	4.2	50.9	9.0	64.5	18.4
		10	58.9	10.3	56.8	5.8	52.9	12.1	56.2	5.5
		15	47.6	4.2	56.9	15.3	49.3	13.5	51.3	9.7

Figure 2. (A) Matrix effect of pork with different dilution ratios, using PBS containing 5 mM MgCl₂ as an extraction buffer. (B) Matrix effect of pork (fat removed), with different dilution ratios using PBS containing 5 mM MgCl₂ as an extraction buffer. (C) Matrix effect of pork with different dilution ratios of PBS containing 5 mM MgCl₂ and 0.1% BSA.

Figure 3. (A) Matrix effect of egg samples using different volumes EtoAC as an extraction buffer. (B) The effect of EtoAC concentration on recovery and OD_max values. (C) Matrix effect of egg samples using mixed solvent (4 mL ethyl acetate and 2 mL acetonitrile) as an extraction buffer. (D) Matrix effect of egg samples with different dilution ratios of PBS containing 5 mM MgCl₂ and 0.1% BSA as extraction buffer.

Figure 4. (A) Matrix effect of honey samples extracted with different dilution ratios. (B) The effect of pH values on the recovery and OD_max values. (C) The effect of extraction times on recovery and OD_max values. (D) Matrix effect of honey samples with PBS added and different dilution ratios. (E) The effect of different extraction solvents on recovery and OD_max values. (F) The standard curves of SMZ in honey sample extract by SCX.