FSTest™ Rhodamine B Rapid Test Kit (10 Tests/Kit)
Product Overview
The FSTest™ Rhodamine B Rapid Test Kit is a premium, high-performance screening solution designed for the rapid qualitative detection of Rhodamine B contamination in condiments and oils. Rhodamine B is an industrial fluorescent dye commonly used in textiles. Due to its bright red hue and low cost, it is sometimes illegally used by unscrupulous vendors as an adulterant in food color sense modification, despite being highly carcinogenic and toxic. By uniquely combining Solid Phase Extraction (SPE) column purification with a highly sensitive competitive lateral flow immunochromatographic assay, this kit effectively eliminates complex pigment matrices to provide clean, laboratory-grade accuracy directly on the field.
Dual-Action Test Principle
This kit utilizes an advanced two-tier separation and screening mechanism to guarantee high-fidelity results:
• Selective SPE Separation: During sample pretreatment, the raw liquid extract passes through a dedicated Rhodamine B Solid Phase Extraction (BSPE) adsorbent column. Food pigments and impurities are washed away, while the targeted Rhodamine B analyte is selectively retained, purified, and subsequently concentrated.
• Competitive Gold Assay: The purified eluate reacts via a competitive immunochromatographic assay. Rhodamine B in the sample competes with pre-immobilized antigens on the test line (T line) for colloidal gold-labeled antibodies.
Result | Visual Line Interpretation | Diagnostic Meaning |
Positive (+) | High contamination inhibits binding, making the T line visibly lighter than the C line, or completely invisible. | Rhodamine B contamination is present in the sample matrix. |
Negative (-) | The T line develops a deep color equal to or darker than the C line. | Rhodamine B is absent or trace levels are below the detection threshold. |
Invalid | The Control line (C line) fails to appear, regardless of whether the T line is visible or not. | The test run is invalid. The test must be repeated using a new cassette. |
Target Industries & Applicable Matrices
This heavy-duty pigment matrix-busting kit is vital for chili export/import verification bureaus, condiment manufacturing lines, wholesale spice markets, third-party food testing institutions, and agricultural enforcement regulators. It is fully optimized for:
· • Chili powder
· • Chili paste
· • Tomato sauce (with added extraction enhancements)
· • Chili oil
Key Advantages & Application Scenarios
· Trace-Level Sensitivity (5 μg/kg LOD): Delivers an outstanding Limit of Detection (LOD) of 5 μg/kg, making it highly effective for filtering out low-concentration dye adulteration.
· Unmatched Specificity (No False Positives): Shows zero cross-reactivity with other heavily used food colorings. Samples containing up to 100 μg/L of Sudan Red, Sunset Yellow, Amaranth, and Tartrazine all yield clean, negative results.
· Bypasses Heavy Machinery: Offers a completely mobile, self-contained workflow. It functions as a powerful field alternative to high-end liquid chromatography (HPLC) methods, allowing testing directly on processing floors or ports within 1 hour of pack opening.
Simple Step-by-Step Assay Procedure
Achieve absolute visual chemical validation using these professional steps:
1. Extraction & Layer Separation:
• Chili Powder/Paste/Oil: Weigh 2.0 ± 0.1 g of homogenized sample into a 15mL centrifuge tube.
• Tomato Sauce: Weigh 2.0 ± 0.1 g into a 15mL tube and add 3g of Sodium Chloride (NaCl).
Add 8mL of Extraction Solution, shake vigorously for 2 minutes (or sonicate for 5 mins), and let layers separate until clear (centrifuge at 4000 r/min for 2 min if turbid).
2. SPE Column Purification:
Load 2.5mL of the upper clear supernatant onto the top of the BSPE column. Apply gentle pressure using an ear-washing bulb to maintain a flow rate of ~2 drops/s, then discard the flow-through filtrate.
Wash by adding 2mL of Washing Solution through the column at 2 drops/s and discard the filtrate.
Elute by positioning the column over a 10mL centrifuge tube, add 0.4mL of Elution Solution, press through at 1 drop/s, and collect the purified eluate.
3. Evaporation & Reconstitution:
Dry the collected eluate entirely under a nitrogen or air dryer stream at 65–90°C.
Add 400 µL of Reconstitution Solution and vortex for 30 seconds to fully dissolve the chemical residue.
4. Gold Cassette Loading:
Bring the cassette to room temperature (20–40°C). Pipette 100 µL of the reconstituted solution into a microwell, mix 3–5 times, and let it react for 3 minutes.
Transfer the entire volume into the sample well of the cassette. Interpret the visual lines between 5–8 minutes.
Kit Composition & Storage
• Specifications: 10 tests/kit.
• Included Contents: 10 Test Cassettes, 10 Microwells, 2x Extraction Solution (50mL), 1x Reconstitution Solution (8mL), 1x Washing Solution (25mL), 1x Elution Solution (8mL), 10x BSPE Columns, 10x 10mL Centrifuge Tubes, 10x 15mL Centrifuge Tubes, and a User Manual.
• Storage Conditions: Stored tightly sealed at 1–30°C in a cool, dry place. Do not freeze. Extended shelf-life is 18 months.
Get in Touch with Us Today!
Protecting your international brand reputation from harmful industrial dyes demands rapid, unambiguous testing metrics. Reach out to our technical application engineers today to request wholesale distribution tier quotes, buy a sample kit, or query compatibility parameters.
