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CN-121994782-A - Method for detecting 1, 2-propylene glycol in high-absorptivity resin

CN121994782ACN 121994782 ACN121994782 ACN 121994782ACN-121994782-A

Abstract

The invention discloses a method for detecting 1, 2-propylene glycol in high-absorptivity resin, which is characterized in that a methanol solution is used for extracting a sample, so that the water absorption swelling of sodium polyacrylate resin is effectively inhibited, and the high-precision detection of trace 1, 2-propylene glycol is realized by combining sodium periodate oxidation and acetylacetone color development. The recovery rate of the method is more than or equal to 98 percent, the relative standard deviation is less than or equal to 2 percent, and the method is obviously superior to the traditional water extraction method, and is suitable for industrial quality control of sanitary products, agricultural water-retaining agents and the like.

Inventors

  • ZHONG SHENGHUI
  • YANG WEIDONG
  • LIU RUODUO
  • WU YANMIN
  • TANG WENLI
  • YAO JUANJUAN
  • LI HAN
  • RUAN YULIN

Assignees

  • 浙江卫星新材料科技有限公司

Dates

Publication Date
20260508
Application Date
20251229

Claims (10)

  1. 1. The method for detecting the 1, 2-propylene glycol in the high-absorptivity resin is characterized by comprising the following steps of: S1, sample extraction, namely mixing resin to be detected with methanol solution, adopting ultrasonic extraction, and centrifuging to obtain supernatant after the extraction is completed; S2, oxidizing reaction, namely taking supernatant, adding sodium periodate solution, adjusting the pH to 4.0-5.0, and then carrying out light-shielding reaction; s3, color development measurement, namely adding sodium thiosulfate to quench residual oxidant, adding a color developing agent, heating in a water bath, cooling to room temperature, measuring absorbance at 410-414nm, and calculating the content of 1, 2-propanediol according to a formaldehyde standard curve.
  2. 2. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 1, wherein the extracted supernatant is purified by a solid phase extraction column, and the filler of the solid phase extraction column is C18 silica gel or PSA-graphitized carbon black composite filler.
  3. 3. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 2 wherein the step of activating the solid phase extraction column comprises pretreatment with 5mL of methanol and 5mL of 65% methanol solution in this order.
  4. 4. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 1 wherein the concentration of the methanol solution is 60-70% and the mass to volume ratio of the resin to be measured to the methanol solution is 1:15-20 (g/mL).
  5. 5. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 1 wherein the power of the ultrasonic extraction is 200-300W, the temperature is 40-50 ℃ and the extraction time is 20-40min.
  6. 6. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 1 wherein in step S2, dilute sulfuric acid is used to adjust the pH.
  7. 7. The method for detecting 1, 2-propanediol in a superabsorbent resin according to claim 1, wherein in step S2, the sodium periodate solution contains an acetic acid-sodium acetate buffer system having a ph of 4.5, and the amount of the acetic acid-sodium acetate buffer system added is 0.8 to 1.2 times the volume of the extract.
  8. 8. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 1 wherein in step S3, the color-developing agent is an ascorbyl-containing acetylacetone-ammonium acetate comprising 25% ammonium acetate, 0.5% acetylacetone, 0.2% glacial acetic acid, 0.1-0.3% ascorbic acid (w/v).
  9. 9. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 1 wherein in step S3, the water bath heating is carried out at a temperature of 95-100 ℃ for a period of 10-20min.
  10. 10. The method for detecting 1, 2-propanediol in a superabsorbent resin of claim 1 wherein in step S1, the aqueous methanol solution contains disodium EDTA at a concentration of 0.5%.

Description

Method for detecting 1, 2-propylene glycol in high-absorptivity resin Technical Field The invention relates to the technical field of detection of 1, 2-propylene glycol, in particular to a method for detecting 1, 2-propylene glycol in high-absorptivity resin. Background Sodium polyacrylate superabsorbent resins (SAP) are widely used in the fields of sanitary articles, agricultural water-retaining agents, and the like. During its production 1, 2-propanediol may remain in the final product. Since 1, 2-propanediol has a certain biotoxicity, its residual amount in the related products needs to be strictly limited. The current method for detecting 1, 2-propylene glycol mainly comprises gas chromatography and high performance liquid chromatography. However, these methods have problems of expensive equipment, complicated operation, complicated pretreatment, etc., and are difficult to popularize and apply in production enterprises. More importantly, sodium polyacrylate SAP swells rapidly to form gel (the water absorption rate can reach more than 300 g/g) after meeting water, and the traditional extraction method can not effectively release 1, 2-propanediol wrapped in a gel network, so that the extraction efficiency is low (usually less than 65 percent), and the detection accuracy is seriously affected. In the prior art, the detection method based on gas chromatography requires complicated derivatization treatment, the single detection time exceeds 3 hours, and the equipment cost is high. The traditional periodic acid oxidation-color development method is low in cost, but is only suitable for liquid samples, and the recovery rate is only 45-60% when the method is directly used for SAP detection, so that the detection requirement cannot be met. Therefore, the development of the 1, 2-propanediol detection method capable of effectively solving the SAP gelation problem, improving the extraction efficiency and simultaneously guaranteeing the detection accuracy has important significance. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a method for detecting 1, 2-propylene glycol in high-absorptivity resin, and solves the problems of low extraction efficiency and poor detection accuracy in the prior art. In order to achieve the technical effects, the invention adopts the following scheme: A method for detecting 1, 2-propylene glycol in high-absorptivity resin comprises the following steps: S1, sample extraction, namely mixing resin to be detected with methanol solution, adopting ultrasonic extraction, and centrifuging to obtain supernatant after the extraction is completed; S2, oxidizing reaction, namely taking supernatant, adding sodium periodate solution, adjusting the pH to 4.0-5.0, and then carrying out light-shielding reaction; s3, color development measurement, namely adding sodium thiosulfate to quench residual oxidant, adding a color developing agent, heating in a water bath, cooling to room temperature, measuring absorbance at 410-414nm, and calculating the content of 1, 2-propanediol according to a formaldehyde standard curve. According to the preferred technical scheme, the extracted supernatant is purified by a solid phase extraction column, and the filler of the solid phase extraction column is C18 silica gel or PSA-graphitized carbon black composite filler. According to the preferred technical scheme, the solid phase extraction column is subjected to pretreatment by using 5mL of methanol and 5mL of 65% methanol solution in sequence. According to the preferred technical scheme, the concentration of the methanol solution is 60-70%, and the mass-volume ratio of the resin to be tested to the methanol solution is 1:15-20 (g/mL). According to the preferred technical scheme, the power of ultrasonic extraction is 200-300W, the temperature is 40-50 ℃, and the extraction time is 20-40min. In the preferred technical scheme, in the step S2, dilute sulfuric acid is adopted to adjust the pH value. In the preferred technical scheme, in the step S2, the sodium periodate solution contains an acetic acid-sodium acetate buffer system with the pH of 4.5, and the addition amount of the acetic acid-sodium acetate buffer system is 0.8-1.2 times of the volume of the extracting solution. In the preferred technical scheme, in the step S2, the molar concentration of the sodium periodate solution is 0.05-0.1 mol/L. In a preferred embodiment, in step S3, the color-developing agent is acetylacetone-ammonium acetate containing 0.1-0.3% ascorbic acid, including 25% ammonium acetate, 0.5% acetylacetone, 0.2% glacial acetic acid, and 0.1-0.3% ascorbic acid (w/v). In the preferred technical scheme, in the step S3, the temperature of the water bath heating is 95-100 ℃ and the time is 10-20min. In the preferred technical scheme, in the step S3, the cooling mode adopts ice bath cooling, and the temperature of the ice bath cooling is 0-4 ℃. In a preferred embodiment, in step S1, the aqueous methanol