AU2005100334A4 - Device for the detection of nitrate residues - Google Patents

Description

Description 0 Numerous test kits and prior art patents exist for the presumptive identification of nitrate residues.

SCurrent nitrate residue field testing kits employ ?liquid reagents?, including acids, bases and solvent and are cumbersome, requiring manual handling of ampoules, breaking vials, reagent bottles and often sample clean up prior to analysis. All these ?multi step? sequences are employed to improve shelf life storage and viability of the kit, manufacture and shipping, and enhance en e sensitivity and selectivity for nitrate residue detection.

tfl It would be highly advantageous to have a simplified presumptive nitrate test device, free of 0 o hazardous liquid reagents, cumbersome packaging and time consuming multi-step reaction sequences. Such an improvement would be innovative and improve tremendously the manufacture, shipping and end use and reduce the cost of the final device.

In accordance with this invention the said device contains all chemicals either in dry formulation or impregnated into bibulous carrier capable of presumptive colorimetric indication in the presence of nitrate residues.

In accordance with this invention the device offers moisture UV retarding environment by encapsulating or impregnating said reagents within inert moisture UV retarding environment.

In accordance with this invention the device is in the form of a pressed article, e.g. tablet, or dry coating on a solid support paper, plastic, wood), or impregnated bibulous carrier, in all cases providing a surface upon which the colorimetric reaction can take place.

In accordance with this invention the pressed article may be manufactured by milling together and homogenising all dry reagents and moisture UV retarding chemicals to form a fine dry powder and pressing the powder into desired article shape, e.g. tablet. Or impregnating all chemicals within a suitable inert bibulous carrier.

In accordance with this invention the dry coated surface may be produced by suspending all dry reagents and moisture UV retarding chemicals in a non-aqueous solvent which is capable of dissolving the moisture UV retarding chemicals and dipping a solid support article into said liquid in suspension, removing solid support and drying, thus producing a dry reagent coated article with a 0 Ssurface capable of being rubbed by a swab facilitation a colorimetric indication.

In accordance with this invention the dry reagents and moisture UV retarding chemicals are chosen to enhance sensitivity and shelf life viability, reduce porosity between individual reagent particles, reduce moisture and UV degradation and simplify manufacture and end use, while reducing device cost.

en3 en3 0 In accordance with this invention, the device comprises a simple cotton swab, moistened with in water/DMSO, for collecting a sample and rubbing surface of said device, facilitating a colorimetric Sindication.

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Claims (4)

1. A dry moisture UV protected, solid hand held, in-situ, nitrate residue presumptive colorimetric detection device, which excludes the need for bulky packaging by impregnating all necessary reagents within an inert bibulous carrier, including but not limited to: glass microfiber (GFM) filter paper, rock wool, whatman or advantec acid washed papers, or 2, 3 or 4 grades. eCn

2. A dry hand held in-situ nitrate residue detection device as claimed in 1, wherein all reagents 0 O solid long-chain fatty acids and their salts, stearic acid, magnesium stearate, anhydrous sodium tf sulphate, zinc oxide, octylmethoxycinnamate, butylmethoxybenzoylmethane, octylsalicylate, 0 O sodium lauryl sulphate, sodium bisulphate, ammonium bisulphate, trichloroacetic acid, trifluoroacetic acid, analine sulphate, barium chloride, brucine, cupric-tetrapyridine, diphenylamine, griess reagent pre-mix, J-Acid, K-Acid, I-Acid, Nitron, potassium iodide, mercuric chloride, methylene blue, silver nitrate, dithiocarbamate, thymol blue, potassium hydroxide, sodium hydroxide, tetraalkylammonium hydroxide, anthranillic acid, alphanaphthylamine, sulphanillic acid, sulphanillamide, p-aminobenzoic acid, N-(1-naphthyl)ethylenediamine dihydrochloride, sodium arsenite, picric acid, p-anisidine, o-anisidine, oxalic acid, citric acid, tartaric acid, nano- sized zinc powder, ammonium chloride, diphenylhydrazine, thiosulphate salts, metabisulphite salts, ascorbic acid, stannous chloride, titanium trichloride, dimethylamniobenzaldehyde, diethylaminobenzaldehyde, dimethylaminocinnamaldehyde, sodium periodate, potassium permanganate are impregnated within GFM paper, rock wool, and the like, which enables inert storage of reagents while allowing instant mixing with analyte on contact with sample swab.

3. A dry hand held in-situ nitrate residue detection device as claimed in land 2 wherein the reagents and in particular sulphanilamide (0.01-0.5g), preferably 0.3g, N-(1-naphthyl)ethylenediamine dihydrochloride (0.01 0.3g), preferably 0.lg, nano-zinc powder (0.01 0.2g) preferably 0.lg is added to acetone (5mL), thus making solution A, to this is applied Advantec #2 paper is applied to solution A, vigerously shaken, removed and dried, thus making paper A.

4. A dry hand held in-situ nitrate residue detection device as claimed in 1-3, wherein Sodium bisulphate (5 50g), preferably 18g is dissolved in water (10 100mL), preferably 30mL, thus making solution B, into this GFM or Advantec #2 paper is dipped dried thus making paper B. A dry hand held in-situ nitrate detection device as claimed in 1-4 wherein a small square of paper A is applied to doubled sided tape, over layed on this is a larger square of paper B, applied to this is a swab (cotton or rayon) containing water/DMSO (20:80), used for sample collection and spotting onto reagent strips affording a presumptive pink indication in the presence of nitrate.