1. Brief

This product is used for testing Nitrofuran(SEM) residue in honey samples. The whole testing needs about 2h, suitable for all kinds of enterprises and inspection agencies.

The detection limit is 0.5ppb（ug/kg）

2. Components

1) Nitrofuran (SEM) colloidal gold rapid test strip

(Including tablet, gold label well, dropper, desiccant) 50 pieces/kit

2) Manuals                                             1 piece/kit

3) 2-Nitrobenzaldehyde (C₇H₅NO₃)                        1 bottle/kit

4) Nitrofuran redissolving solution                         1 bottle/kit

3. Equipments required but not provided

Micropipettes, nitrogen-drying device or air-drying device, water bath, centrifuge, balance (a reciprocal sensibility of 0.01 g);

4. Sample preparation]

1) Weigh 3g honey sample into 50ml centrifuge tube, add 4ml deionized water, 0.5ml 1M HCl, 0.2ml 2-Nitrobenzaldehyde (C₇H₅NO₃), mix thoroughly for 3 min;

2) Incubate in water bath at 60℃ for 1h;

3) Take the tube out from the water bath, add 5ml 0.1M K₂HPO₄, 0.4ml 1M NaOH, 6ml ethyl acetate, mix thoroughly for 1min, centrifuge at 4000r/min for 5min;

4) Take 3ml supernatant into 5ml centrifuge tube, blow to dry by air at 60℃;

5) Add 0.5ml N-hexane and 0.3ml nitrofuran redissolving solution to the dry tube, mix evenly, centrifuge at 4000r/min for 1min (or put aside until stratification);

6) Use Micropipettes to absorb 100ul down-layer solution into gold label well, ready to test.

5. Operation procedures

1) Read the Instruction, return the reagents to room temperature (20℃~30℃) before testing.

2) Take out the test strip, put it on desk flatly, as the following picture on the right. (Use it immediately after opening the package.)

3) Absorb 100μL solution into gold label well, wait for 2 min, use small dropper to blow and beat until the red material is completely dissolved, wait to react for 2min,

4) Use dropper absorb all sample from the well, vertically add it into sample collecting well (as following picture), timing after adding sample.

5) Read the result in 5-8 minutes, otherwise it is invalid.

6. Test Result Interpretation

6.1 Negative (—):  T line appears (T line, near Sample Collecting Region), T line is darker or has the same color with C line, it means the SEM concentration is lower than detection limit or no SEM residue.

6.2 Positive (+): T line is lighter than C line or T line is invisible, it means the SEM concentration is higher than detection limit. The more lighter of T line compared with C line, the higher content of SEM in sample.

6.3 Invalid: C line is invisible, maybe it is the operation error or test strip is invalid. Read the Instruction, use new test strip to test again.

7. Precautions

1) Test at 20℃~30℃ environment.

2) Wear gloves when testing.

3) Do not eat any of the reagents.

4) Do not use test card out of expiry date.

5) Do not touch the white membrane surface in the middle of test card.

6) Do not repeat use the dropper, to avoid cross pollution.

8. Storage and expiry date

Storage:  Store at 4-30 ℃ in dark, no frozen.

Expiry date: 12 months; date of production is on box.