阅读说明：本技术 一种快速检测餐饮具中阴离子合成洗涤剂的试剂盒及方法 (Kit and method for rapidly detecting anionic synthetic detergent in tableware ) 是由 李涛 杨若朦 王建山 林芳 刘海静 宋莉 赵俊楠 郭建博 吕卓 李红梅 马元斌 于 2020-04-03 设计创作，主要内容包括：本发明公开了一种快速检测餐饮具中阴离子合成洗涤剂的试剂盒及方法,涉及食品安全检测技术领域。所述试剂盒包括样品提取管、提取液、无机碱溶液、指示剂溶液、无机酸溶液、萃取液和显色溶液、离心管和标准比色卡；所述提取液为超纯水,所述无机碱溶液为氢氧化钠溶液,所述指示剂溶液为酚酞指示剂溶液,所述无机酸溶液为硫酸溶液,所述萃取液为三氯甲烷和二氯甲烷中的至少一种,所述显色溶液为亚甲蓝溶液。本发明提供了一种操作简便、成本低廉、速度快、灵敏度高的能现场快速检测餐饮具中阴离子合成洗涤剂的方法,不需要专门的仪器设备,耗时短,适合于现场快检。(The invention discloses a kit and a method for rapidly detecting an anion synthetic detergent in tableware, and relates to the technical field of food safety detection. The kit comprises a sample extraction tube, an extracting solution, an inorganic alkali solution, an indicator solution, an inorganic acid solution, an extraction liquid, a developing solution, a centrifugal tube and a standard colorimetric card; the extracting solution is ultrapure water, the inorganic alkali solution is a sodium hydroxide solution, the indicator solution is a phenolphthalein indicator solution, the inorganic acid solution is a sulfuric acid solution, the extracting solution is at least one of trichloromethane and dichloromethane, and the developing solution is a methylene blue solution. The invention provides a method for rapidly detecting the anionic synthetic detergent in tableware on site, which has the advantages of simple and convenient operation, low cost, high speed and high sensitivity, does not need special instruments and equipment, has short time consumption and is suitable for rapid detection on site.)

1. A kit for rapidly detecting anion synthetic detergent residues in tableware is characterized by comprising a sample extraction tube, an extracting solution, an inorganic alkali solution, an indicator solution, an inorganic acid solution, an extracting solution, a developing solution, a centrifuge tube and a standard colorimetric card;

the extracting solution is ultrapure water, the inorganic alkali solution is a sodium hydroxide solution, the indicator solution is a phenolphthalein indicator solution, the inorganic acid solution is a sulfuric acid solution, the extracting solution is at least one of trichloromethane and dichloromethane, and the developing solution is a methylene blue solution.

2. The kit according to claim 1, wherein the concentration of the sodium hydroxide solution is 0.4mol/L to 3 mol/L.

3. The kit of claim 1, wherein the phenolphthalein indicator solution is at a concentration of 0.5g/L to 2 g/L.

4. The kit according to claim 1, wherein the concentration of the sulfuric acid solution is 0.2mol/L to 1.5 mol/L.

5. The kit of claim 1, wherein the methylene blue solution is prepared by mixing methylene blue, sulfuric acid, sodium dihydrogen phosphate and an extracting solution.

6. The kit according to claim 5, wherein the ratio of the mass of methylene blue, the volume of sulfuric acid, the mass of sodium dihydrogen phosphate and the volume of the extracting solution in the methylene blue solution is 30 mg: 6.8 mL: 50 g: 1L of the compound.

7. A method for rapidly detecting anionic synthetic detergent residues in tableware by using the kit of any one of claims 1 to 6, wherein the method comprises the following steps:

step 1, preparation of sample liquid:

selecting a sample to be tested, adding a proper amount of extracting solution, and fully washing tableware to obtain a sample solution;

step 2, extracting a sample solution:

adding an appropriate indicator solution, an inorganic alkali solution, an inorganic acid solution, a color developing solution and an extraction liquid into the sample liquid in sequence, mixing uniformly, and standing to obtain a solution to be detected;

step 3, colorimetric determination:

and observing the color of the lower layer of test solution, and determining the result by carrying out colorimetric determination on the test solution and a standard color scale solution or a standard colorimetric card.

8. The method according to claim 7, wherein the volume of the extract solution added in step 1 is 10mL-30 mL.

9. The method of claim 7, wherein in step 3, the standard color-scale solution or the standard color chart is prepared by the following steps:

(1) preparing a sodium dodecyl benzene sulfonate standard solution with known concentration by using the extracting solution as a solvent;

(2) respectively adding an appropriate indicator solution, an inorganic alkali solution, an inorganic acid solution, a developing solution and an extraction liquid into the standard solution in sequence, uniformly mixing, standing for layering, and observing the color of the lower layer solution to obtain the standard color gradation solution;

(3) finding out corresponding standard colors on a common color card according to the colors of the lower layer solution of the standard color gradation solution, and printing a standard color comparison card according to the color values of the standard colors.

10. The method according to claim 9, wherein in the step (1), the standard solution of sodium dodecylbenzenesulfonate with known concentration comprises standard solutions of sodium dodecylbenzenesulfonate with concentrations of 5mg/L, 10mg/L, 20mg/L, 40mg/L and 80 mg/L.

Technical Field

The invention relates to the technical field of food safety detection, in particular to a kit and a method for rapidly detecting an anion synthetic detergent in tableware.

Background

The anionic synthetic detergent, namely the main component of detergent such as washing powder, detergent, laundry detergent, soap and the like which are frequently used in daily life, is a low-toxicity substance, is widely used for cleaning tableware in life due to the advantages of convenient use, easy dissolution, good stability, low cost and the like, but if the tableware is not fully washed in the cleaning process, the detergent is left on the tableware. Can be accumulated in human body through food chain, and is harmful to human health, and can cause acute poisoning of human body due to improper cleaning of anion synthetic detergent, wherein the poisoning mainly shows central nervous system and gastrointestinal tract symptoms. In view of this, GB 14934-2016 (national food safety Standard) Disinfection tableware sets) stipulates that the anion synthetic detergent for tableware (drinking) by chemical disinfection should not be detected. The national and provincial supervision departments at all levels have the emphasis on the spot check monitoring of the anionic synthetic detergent residues of tableware and kitchenware. The general flow of inspection is that law enforcement personnel carry out the spot check sample from food circulation places such as dining room, send to the detection laboratory, detect through special check-out set, appear unqualified sample after, carry out punishment to being checked the mechanism again.

GB/T5750.4-2006 provides a method for measuring an anionic synthetic detergent in water by using a methylene blue spectrophotometry, the two methods are general authoritative methods of domestic professional detection institutions at present, and the detection result is very accurate. However, the method needs to adjust the pH value of a water sample and then add chloroform for multiple extractions, is complex, needs a spectrophotometer, needs professional detection personnel, is long in time consumption, high in cost and complex in steps, is long in flow time and high in detection cost, and can be used for detecting unqualified samples in many cases. In view of the particularity of tableware in the circulation link, a method suitable for on-site rapid detection is urgently needed to be developed.

Although the method for detecting the chloroform by the royal jelly and the like is improved aiming at the national standard detection method, the chloroform is adopted for one-time extraction, the steps are shortened, the working strength of detection personnel is reduced, and the using amount of the chloroform is reduced, but the method is still bound by using large instruments and operation steps, and the rapid on-site detection cannot be realized.

Chinese patent application 201811601752.8 discloses a method for detecting an anion synthetic detergent, which comprises the following steps: diluting an anionic surfactant, and diluting the anionic surfactant with pure water to obtain a standard use solution of the anionic surfactant; taking a proper amount of water sample, and placing the water sample in a colorimetric tube; additionally sucking the sodium dodecyl benzene sulfonate standard use solution and placing the solution in a 50mL colorimetric tube to form a standard series; adding methylene blue solution into the sample tube and the standard series respectively, stirring, adding chloroform, pre-shaking for more than two times, then deflating, continuing stirring and shaking, and standing for layering for 30-40 min; and (3) extracting the trichloromethane from the sample, filtering, taking a 12 mL-scale suction pipe after treatment, sealing the top end of the suction pipe, quickly and directly inserting the suction pipe into the bottom of the colorimetric pipe for sucking the trichloromethane layer solution, taking out the filter paper, slightly wiping the mouth of the suction pipe, transferring the mouth of the suction pipe into a 1cm cuvette, and measuring the absorbance of the cuvette. However, the detection still needs an ultraviolet spectrophotometer, and the shortest time is about 70min after technical reproduction and detection according to the method according to the specification, which is undoubtedly not capable of meeting the requirement for solving the technical problem of rapid detection.

In view of this, the present application addresses the need for realizing rapid on-site detection for the particularity of tableware in the circulation link.

Disclosure of Invention

The invention aims to develop a kit and a method for rapidly detecting an anion synthetic detergent in tableware.

The present invention utilizes methylene blue dye and anion synthetic detergent in water solution to form blue compound easy to be extracted by organic solvent, and then compares the shade of blue in organic phase with standard colour card so as to judge the residue of anion synthetic detergent in tableware.

In order to complete the experimental purpose, the invention provides a kit and a method for rapidly detecting the residue of an anionic synthetic detergent in tableware.

On one hand, the kit comprises a sample extraction tube, an extracting solution, an inorganic alkali solution, an indicator solution, an inorganic acid solution, an extracting solution, a developing solution, a centrifuge tube and a standard colorimetric card.

Furthermore, the extracting solution is ultrapure water, and meets the requirement of primary water specified in GB/T6682.

Further, the inorganic alkali solution is a sodium hydroxide solution, and the concentration is 0.4-3 mol/L.

Furthermore, the indicator solution is phenolphthalein indicator solution, and the concentration is 0.5g/L-2 g/L.

Further, the inorganic acid solution is a sulfuric acid solution, and the concentration is 0.2-1.5 mol/L.

Further, the extract is at least one of chloroform and dichloromethane.

Further, the color developing solution is a methylene blue solution, the methylene blue solution is formed by mixing methylene blue, sulfuric acid, sodium dihydrogen phosphate and an extracting solution, and the ratio of the mass of the methylene blue, the volume of the sulfuric acid, the mass of the sodium dihydrogen phosphate and the volume of the extracting solution in the methylene blue solution is 30 mg: 6.8 mL: 50 g: 1L of the compound.

On the other hand, the method is implemented according to the following steps:

step 1, preparation of sample liquid:

selecting a sample to be tested, adding a proper amount of the extracting solution in the step 1, and fully washing tableware to obtain a sample solution;

step 2, extracting a sample solution:

adding an appropriate indicator solution, an inorganic alkali solution, an inorganic acid solution, a color developing solution and an extraction liquid into the sample liquid in sequence, mixing uniformly, and standing to obtain a solution to be detected;

step 3, colorimetric determination:

the color of the lower layer sample solution was observed, and the result was judged by a colorimetric assay.

Further, the extracting solution is ultrapure water, the inorganic alkali solution is a sodium hydroxide solution, the indicator solution is a phenolphthalein indicator solution, the inorganic acid solution is a sulfuric acid solution, the extracting solution is at least one of chloroform and dichloromethane, and the developing solution is a methylene blue solution. Furthermore, the extracting solution is ultrapure water meeting the requirement of primary water specified in GB/T6682, the inorganic alkali solution is a sodium hydroxide solution with the concentration of 0.4-3 mol/L, the indicator solution is a phenolphthalein indicator solution with the concentration of 0.5-2 g/L, the inorganic acid solution is a sulfuric acid solution with the concentration of 0.2-1.5 mol/L, the extracting solution is one of trichloromethane and dichloromethane, the developing solution is a methylene blue solution and is formed by mixing methylene blue, sulfuric acid, sodium dihydrogen phosphate and the extracting solution, and the ratio of the mass of the methylene blue, the volume of the sulfuric acid, the mass of the sodium dihydrogen phosphate and the volume of the extracting solution in the methylene blue solution is 30 mg: 6.8 mL: 50 g: 1L of the compound.

Further, the volume of the added extracting solution in the step 1 is 10mL-30 mL.

Further, the amount of the indicator solution added in the step 2 is 1-3 drops, the amount of the inorganic alkali solution is 1-3 drops, and the amount of the inorganic acid solution is 1-3 drops, wherein the inorganic alkali solution is added to change the extracting solution into pink, and the inorganic acid is added until the extracting solution just turns colorless. Adding the developing solution with the volume of 8-12 mL and the extracting solution with the volume of 4-6 mL.

Further, in the step 2, the uniformly mixing mode is shaking forcibly, the shaking time is not less than 2min, and the standing time is not less than 3min until layering is obvious.

Further, the colorimetric determination method is visual colorimetry with a standard color gradation solution or a colorimetric card. Comparing with standard color scale solution or colorimetric card, judging the content of anion synthetic detergent (sodium dodecyl benzene sulfonate) in the sample, if the color is darker than the detection limit, the sample is positive, otherwise, the sample is negative.

Further, the standard color scale solution or the color chart is manufactured according to the following steps:

(1) preparing a sodium dodecyl benzene sulfonate standard solution with known concentration by using the extracting solution as a solvent;

(2) respectively adding an appropriate indicator solution, an inorganic alkali solution, an inorganic acid solution, a developing solution and an extraction liquid into the standard solution in sequence, uniformly mixing, standing for layering, and observing the color of the lower layer solution to obtain the standard color gradation solution;

(3) finding out corresponding standard colors on a common color card according to the colors of the lower layer solution of the standard color gradation solution, and printing a standard color comparison card according to the color values of the standard colors.

As some illustrative examples, the standard color-scale solution or the color chart is prepared by the following steps:

(1) preparing standard solutions of sodium dodecyl benzene sulfonate with the concentrations of 5mg/L, 10mg/L, 20mg/L, 40mg/L and 80mg/L respectively by using the extracting solution as a solvent;

(2) precisely transferring 1mL of the standard solution into each colorimetric tube, adding 19mL of the extracting solution, and uniformly mixing for three minutes to obtain a standard sample solution;

(3) sequentially adding 1 drop of indicator solution and 2 drops of inorganic alkali solution into the standard sample solution to change the solution into pink, then adding inorganic acid solution to ensure that the extracting solution just becomes colorless, then sequentially adding 5mL of chromogenic solution and 5mL of extracting solution, fully shaking for 3min, standing for layering, and observing the color of the lower layer solution to obtain the standard color gradation solution;

(4) finding out corresponding standard colors on a common color chart, printing the standard color chart according to the color values of the standard colors, and performing plastic package storage on the outer surface of the standard color chart.

Compared with the prior art, the invention has the following beneficial effects:

(1) through repeated implementation and determination, the kit and the method provided by the invention take less than 6min for detection, compared with the prior art, the detection time is obviously shortened, and the detection efficiency is improved;

(2) the detection kit and the method of the invention are free from the limit of special instruments and equipment, ensure high sensitivity, meet the requirements of simple operation and low cost, and can be used for on-site quick detection.

Detailed Description

The present invention will be further explained with reference to specific examples in order to make the technical means, the technical features, the technical objectives and the effects of the present invention easier to understand, but the following examples are only preferred embodiments of the present invention, and not all embodiments of the present invention. Based on the embodiments in the implementation, other embodiments obtained by those skilled in the art without any creative efforts belong to the protection scope of the present invention.

In the following examples, unless otherwise specified, all the procedures and equipment used were conventional procedures and equipment used was conventional equipment.