TEST KIT AND DETECTION METHOD FOR ISOTHIAZOLINONES IN TEXTILES

Abstract

The present invention relates to the field of product quality analysis, and specifically, a test kit and detection method for testing isothiazolinone in textiles. A pretreatment step of the present invention adopts a unique process, which may fully transfer isothiazolinone to an acetone and water mixed solution, so that a more accurate measurement result can be achieved. The testing method of the present invention dose not add indicators, does not use large-scale analysis instruments, and is accurate in measurement, easy in reaction termination determination, high in accuracy, low in cost, and strong in popularization and application.

Claims

1. A method for pretreating isothiazolinone in textiles, comprising the following steps: (1) cutting cotton sample into pieces, accurately weighing a certain mass of the tested pieces; (2) heating the pieces obtained in step (1) to 30-60? C., then placing the pieces in an environment with a vacuum degree being 0.060-0.080 MPa for 15-30 min, and removing low boiling point organics affecting measurement; (3) mixing the pieces obtained in step (2) and the acetone and water mixed solution with a mass ratio of 10-15 times, then heating the mixed solution, and maintain a temperature at about 35? C. for 15-30 min; (4) performing sonicate in the mixed solution obtained in step (3) in an ultrasonic wave for 5 min, in order to cause isothiazolinones in textiles to be fully transferred to the acetone and water mixed solution; and (5) filtering the solution obtained in step (4) with a filter paper, washing the pieces with water, and mixing both the filtrated stock solution and washed solution, to obtain isothiazolinones in the pretreated acetone and water mixed solution.

2. The method for pretreating isothiazolinone in textiles as claimed in claim 1, wherein in the acetone and water mixed solution, a volume ratio of acetone to water is 15-3:1.

3. The method for pretreating isothiazolinone in textiles as claimed in claim 1, wherein the heating temperature of the pieces in step (2) is 45-55? C., and the vacuum degree is 0.070-0.075 MPa.

4. A method for rapidly detecting isothiazolinone in textiles, comprising the following steps: step 1, transferring a pretreated acetone and water mixed solution containing the isothiazolinone as claimed in claim 1 to a 25 mL volumetric flask, to make up to volume; step 2, measuring 10 mL of the above standard solution made up to volume, adding 0.5-1 g of an acidic material, after closing, performing uniform stirring, adding a potassium permanganate standard solution to a microburette, then starting titration, and determining that a reaction terminates after the solution changes from colorless to light fuchsia and does not fade within half a minute; and step 3, calculating the content of the isothiazolinone according to a volume of the potassium permanganate standard solution consumed in step 2 and a molar ratio of the isothiazolinone to potassium permanganate during reaction.

5. The method for measuring the content of isothiazolinones as claimed in claim 4, wherein the concentration of the potassium permanganate standard solution is 0.001-1 mol/L.

6. The method for measuring the content of isothiazolinones as claimed in claim 4, wherein the acidic material is a mixed compound of one or two of a sulfuric acid solution, sodium bisulfate, and benzenesulfonic acid with a mass concentration being 15-70%.

7. The method for measuring the content of isothiazolinone as claimed in claim 4, wherein a calculation formula of the number n of moles of the isothiazolinone is: n=C.sub.standard solution?V.sub.standard solution?1000?N.sub.potassium permanganate?N.sub.isothiazolinone?10?25, wherein the unit of n is mol; C.sub.standard solution is the concentration of the potassium permanganate standard solution, in mol/L; V.sub.standard solution is the volume of the potassium permanganate standard solution that titration consumes, in mL; N.sub.potassium permanganate is a stoichiometric coefficient of the potassium permanganate during reaction; N.sub.isothiazolinone is a stoichiometric coefficient of the isothiazolinone during reaction; 25 is a constant volume; and 10 is a volume weighed after making up to volume.

8. The method for measuring the content of isothiazolinone as claimed in claim 4, wherein a calculation formula of the content X.sub.1 or X.sub.2 of the isothiazolinone is: X.sub.1=n?M?m?10.sup.6, X.sub.2=n?m?10.sup.3, wherein the unit of X.sub.1 is mg/kg; the unit of X.sub.2 is mol/kg; n is the number of moles of the isothiazolinone, in mol; M is a molar mass of the isothiazolinone, in g/mol; and m is the mass of accurately weighed textile, in g; and when the isothiazolinone is a mixture, n is a sum of the numbers of moles of all of the isothiazolinone, and M is an average molar mass of all of the isothiazolinone.

9. A method for rapidly detecting isothiazolinone in textiles, comprising the following steps: step 1, transferring a pretreated acetone and water mixed solution containing the isothiazolinone as claimed in claim 2 to a 25 mL volumetric flask, to make up to volume; step 2, measuring 10 mL of the above standard solution made up to volume, adding 0.5-1 g of an acidic material, after closing, performing uniform stirring, adding a potassium permanganate standard solution to a microburette, then starting titration, and determining that a reaction terminates after the solution changes from colorless to light fuchsia and does not fade within half a minute; and step 3, calculating the content of the isothiazolinone according to a volume of the potassium permanganate standard solution consumed in step 2 and a molar ratio of the isothiazolinone to potassium permanganate during reaction.

10. A method for rapidly detecting isothiazolinone in textiles, comprising the following steps: step 1, transferring a pretreated acetone and water mixed solution containing the isothiazolinone as claimed in claim 3 to a 25 mL volumetric flask, to make up to volume; step 2, measuring 10 mL of the above standard solution made up to volume, adding 0.5-1 g of an acidic material, after closing, performing uniform stirring, adding a potassium permanganate standard solution to a microburette, then starting titration, and determining that a reaction terminates after the solution changes from colorless to light fuchsia and does not fade within half a minute; and step 3, calculating the content of the isothiazolinone according to a volume of the potassium permanganate standard solution consumed in step 2 and a molar ratio of the isothiazolinone to potassium permanganate during reaction.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The technical solutions in the embodiments of the present invention are clearly and completely described below. It is apparent that the described embodiments are only part of the embodiments of the present invention, not all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skilled in the art without creative work shall fall within the protection scope of the present invention.

[0029] It should be understood that the specific embodiments described here are merely used to explain the present invention, and are not used to limit the present invention.

Embodiment 1

[0030] A method for pretreating 5-chloro-2-methyl-4-isothiazolin-3-one (CMI) in a cotton textile includes the following steps. [0031] (1) The cotton sample is cut into pieces. 1.345 g of tested pieces are accurately weighed. [0032] (2) The pieces obtained in step (1) are heated to 30-35? C., then the pieces are placed in an environment with the vacuum degree being 0.060-0.065 MPa for 15-30 min, and low boiling point organics affecting measurement are removed. [0033] (3) The pieces obtained in step (2) are mixed with the acetone and water mixed solution with a mass ratio of 10 times, in which a volume ratio of acetone to water is 3:1, then the mixed solution is heated, and the solution temperature is maintained at about 35? C. for 15 min. [0034] (4) Sonicate is performed in the mixed solution obtained in step (3) in an ultrasonic wave for 5 min, in order to cause the CMI therein to be fully transferred to the acetone and water mixed solution. [0035] (5) The solution obtained in step (4) is filtered with a filter paper, the pieces are washed with water. Both filtrated stock solution and washed solution are collected, to obtain the CMI in the pretreated acetone and water mixed solution.

[0036] A method for measuring the CMI content by using the prepared acetone and water mixed solution containing the CMI includes the following steps. [0037] (6) A pretreated acetone and water mixed solution containing the CMI obtained in step (5) is transferred to a 25 mL volumetric flask, to make up to volume. [0038] (7) 10 mL of the above solution obtained in step (6) is measured and transferred to a reaction vessel, then 0.5 g of a sulfuric acid solution with a mass concentration being 25% is added. After closing, uniform stirring is performed, 0.001 mol/L of the potassium permanganate standard solution is added to a microburette, then titration is started. 0.32 mL of the potassium permanganate standard solution is consumed when the solution color changes from colorless to light fuchsia and does not fade within half a minute. [0039] (8) The content of the isothiazolinone is calculated according to the volume of potassium permanganate standard solution consumed in step (7) and the molar ratio of isothiazolinone to potassium permanganate during reaction.

[0040] Chemical reactions of the above analysis method include the following.

##STR00001##

[0041] A calculation formula of the number n of moles of the CMI is shown as follows.

n=C.sub.standard solution?V.sub.standard solution?1000?N.sub.potassium permanganate?N.sub.isothiazolinone?10?25=0.001?0.32?1000?6?5?10?25=7.5?10.sup.?8 mol.

[0042] A calculation formula of the content X.sub.1 or X.sub.2 of the CMI is shown as follows.

X.sub.1=n?M?m?10.sup.6=7.5?10.sup.?8?149?1.345?10.sup.6=8.31 mg/kg.

X.sub.2=n?m?10.sup.3=7.5?10.sup.?8?1.345?103=5.57?10.sup.?5 mol/kg.

[0043] A sample is taken from 15 mL of the remaining sample in the volumetric flask in the step (6), and is measured by a common high-performance liquid chromatography; and a CMI measuring result is 8.31 mg/kg, which is comparable to a measurement result of the present invention and is high in accuracy.

Embodiment 2

[0044] A method for pretreating 2-methyl-4-isothiazolin-3-one (MI) in a silk-containing textile includes the following steps. [0045] (1) The cotton sample is cut into pieces. 1.500 g of tested pieces are accurately weighed. [0046] (2) The pieces obtained in step (1) are heated to 45-55? C., the pieces are placed in an environment with a vacuum degree being 0.070-0.078 MPa for 30 min, and low boiling point organics affecting measurement are removed. [0047] (3) The pieces obtained in step (2) are mixed with the acetone and water mixed solution with a mass ratio of 10 times, a volume ratio of acetone to water is 15:1, then the mixed solution is heated, and a temperature is maintained at about 35? C. for 30 min. [0048] (4) Sonicate is performed in the mixed solution obtained in step (3) in an ultrasonic wave for 5 min, in order to cause the MI therein to be fully transferred to the acetone and water mixed solution. [0049] (5) The solution obtained in step (4) is filtered with a filter paper, the pieces are washed with water. Both the filtrated stock solution and washed solution are collected, to obtain the MI in the pretreated acetone and water mixed solution.

[0050] A method for measuring the content of the MI by using the prepared acetone and water mixed solution containing the MI includes the following steps. [0051] (6) A pretreated acetone and water mixed solution containing the MI obtained in step (5) is transferred to a 25 mL volumetric flask, to make up to volume. [0052] (7) 10 mL of the above solution obtained in step (6) is measured and transferred to a reaction vessel, 0.8 g of benzenesulfonic acid is added. After closing, uniform stirring is performed, 0.002 mol/L of the potassium permanganate standard solution is added to a microburette, then titration is started, and 0.11 mL of the potassium permanganate standard solution is consumed when the solution color changes from colorless to light fuchsia and does not fade within half a minute. [0053] (8) The content of the isothiazolinone is calculated according to the volume of potassium permanganate standard solution consumed in step (7) and the molar ratio of isothiazolinone to potassium permanganate during reaction.

[0054] Chemical reactions of the above analysis method include the following.

##STR00002##

[0055] By adopting the calculation method of Embodiment 1, the following may be obtained.

X.sub.1=n?M?m?10.sup.6=13.65 mg/kg.

X.sub.2=n?m?10.sup.3=9.17?10.sup.?5 mol/kg.

[0056] A sample is taken from 15 mL of the remaining sample in the volumetric flask in the step (6), and is measured by a common high-performance liquid chromatography; and an MI measuring result is 13.94 mg/kg, which is comparable to a measurement result of the present invention and is high in accuracy.

Embodiment 3

[0057] A method for pretreating the CMI and the MI in a polyester-containing textile includes the following steps. [0058] (1) The cotton sample is cut into pieces. 2.123 g of tested pieces is accurately weighed. [0059] (2) The pieces obtained in step (1) are heated to 30-38? C., then the pieces are placed in an environment with a vacuum degree being 0.070-0.075 MPa for 30 min, and low boiling point organics affecting measurement are removed. [0060] (3) The pieces obtained in step (2) are mixed with the acetone and water mixed solution with a mass ratio of 10 times, a volume ratio of acetone to water is 9:1, then the mixed solution is heated, and a temperature is maintained at about 35? C. for 30 min. [0061] (4) Sonicate is performed in the mixed solution obtained in step (3) in an ultrasonic wave for 5 min, in order to cause the CMI and MI therein to be fully transferred to the acetone and water mixed solution. [0062] (5) The solution obtained in step (4) is filtered with a filter paper, the pieces are washed with water. Both the filtrated stock solution and washed solution are collected, to obtain the CMI and MI in the pretreated acetone and water mixed solution.

[0063] A method for measuring the sum content of the CMI and MI by using the prepared acetone and water mixed solution containing the CMI and MI includes the following steps. [0064] (6) A pretreated acetone and water mixed solution containing the CMI and MI obtained in step (5) is transferred to a 25 mL volumetric flask, to make up to volume. [0065] (7) 10 mL of the aboved solution obtained in step (6) is measured and transferred to a reaction vessel, then 1 g of sodium bisulfate is added. After closing, uniform stirring is performed, 0.080 mol/L of the potassium permanganate standard solution is added to a microburette, then titration is started, and 0.38 mL of the potassium permanganate standard solution is consumed when the solution color changes from colorless to light fuchsia and does not fade within half a minute. [0066] (8) The content of the isothiazolinone is calculated according to the volume of potassium permanganate standard solution consumed in step (7) and the molar ratio of isothiazolinone to potassium permanganate during reaction.

[0067] By adopting the calculation methods of Embodiment 1 and Embodiment 2, the following may be obtained.

[0068] X.sub.1=n?M.sub.average?m?10.sup.6=1350.9 mg/kg, and M.sub.average is an average molar mass of the CMI and the MI.

[0069] X.sub.2=n.sub.average?m?10.sup.3=1.02?10.sup.?2 mol/kg.

[0070] A sample is taken from 15 mL of the remaining sample in the volumetric flask in the step (6), and is measured by a common high-performance liquid chromatography; and the sum content between CMI and MI is 1309.4 mg/kg, which is comparable to a measurement result of the present invention and is high in accuracy.

[0071] In order to verify the accuracy of the method in the present invention, the recovery rate and Relative Standard Deviation (RSD) of textiles with different substrates are tested, and results are shown as follows.

[0072] The cotton-containing textile and silk-containing textile without isothiazolinone are used as blanks; standard samples with concentration levels being 3 mg/kg, 6 mg/kg and 9 mg/kg are respectively added; 5 samples are prepared for each concentration level; the recovery rate and RSD are inspected; and results are shown in Table 1 and Table 2.

TABLE-US-00001 TABLE 1 Recovery rate and RSD of cotton-containing textile Addition Recovery rate (%) level CMI MI CMI + MI Blank 3 mg/kg 96.02 95.19 97.19 cotton- 95.41 94.29 91.38 containing 92.28 93.85 97.45 textile 96.21 95.29 90.10 91.42 91.19 90.27 Mean value 94.27 93.96 93.28 RSD 2.13 1.58 3.57 6 mg/kg 98.19 96.21 90.28 92.34 95.24 99.10 99.10 99.21 89.62 94.30 93.67 90.21 98.21 90.28 91.29 Mean value 96.43 94.92 92.10 RSD 2.73 3.10 3.84 9 mg/kg 98.01 98.42 98.21 92.21 99.21 90.28 93.46 90.67 95.21 95.21 94.54 99.23 90.65 90.54 87.23 Mean value 93.91 94.68 94.03 RSD 2.70 3.89 4.90

TABLE-US-00002 TABLE 2 Recovery rate and RSD of silk-containing textile Recovery rate(%) Addition level CMI MI CMI + MI Blank 3 mg/kg 94.21 91.67 101.40 silk-containing 93.21 91.29 90.21 textile 94.79 93.89 92.41 97.09 94.27 91.34 90.25 94.21 89.47 Mean value 93.91 93.07 92.97 RSD 2.37 1.40 4.66 6 mg/kg 95.21 96.78 99.18 93.33 93.56 99.90 92.19 91.34 91.71 94.56 96.58 91.67 94.21 91.52 97.88 Mean value 93.90 93.96 96.07 RSD 1.12 2.51 3.78 9 mg/kg 91.21 92.17 98.99 92.30 92.46 91.27 94.65 90.60 88.68 94.29 95.55 103.25 92.10 97.41 96.30 Mean value 92.91 93.64 95.70 RSD 1.43 2.64 5.47

[0073] The above data show that, the testing method of the present invention has good recovery rate and RSD values for single isothiazolinone. The recovery rate and RSD values of the testing method of the present invention are slightly poor for the mixture of the isothiazolinone, but are still comparable to recovery rate and RSD values of high-performance liquid chromatography, so that the testing method has high promotion and application values.

[0074] The above descriptions are merely the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent transformation made by the description of the present invention under the concept of the present invention, or directly/indirectly applied in other related technical fields are all included in the scope of patent protection of the present invention.