Study On The Methodology Of Safety/quality Parameters Testing And Evaluation For The Disposable Hygiene Products

Disposable hygiene products contact with the human skin and attributed to their advantages of excellent capacity for holding water,convenience and ease of use,etc.,(especially for infants and older people),it has been widely used in daily life.However,safety/quality parameters of these products are important indicators for consumers’ safety and health.Disposable hygiene products are made mostly of nonwovens,fiber and superabsorbent polymers(SAP).The safety risks come from many aspects which may be brought by raw materials,including fluorescent whitening agent in nonwovens and fiber,exceeded content of residual acrylic acid in synthesis of SAP and poor swelling capacity of SAP,etc.China has developed many relevant standard detection parameters for ensuring safety and quality of the products.However,detection methods of some important safety/quality parameters have complicated operations,low sensitivity and poor accuracy,etc.,which are unable to effectively detect safety of these products.Therefore,《the Key Technology Research on the Green Product Certification of Key Field Research-the Key Technology Research on the Green Product Certification of Light and Daily-Chemical Field》has been approved by the National Key Research and Development Program of China(Project number: 2017YFF0211506)in 2017,among which “the Key Technology Research on the Green Product Certification of Diaper” is listed as one of important subproject in the project.Therefore study on the methodology of safety/quality parameters testing and evaluation for the disposable hygiene products are significant for products’ quality and consumers’ health.On one hand,the work using headspace gas chromatography(HS-GC),(1)based on acid-base neutralization and redox reaction,including the reaction between acrylic acid and bicarbonate in solution to form carbon dioxide,the reaction between non-volatile alkylphenol polyethoxylates(APEO)and concentrated hydroiodic acid under high temperature to form iodoethane,the reaction between formaldehyde and sodium borohydride in a concentrated potassium carbonate solution to form methanol,new methods for determining residual acrylic acid in critical raw materials-superabsorbent polymers made of disposable hygiene products,alkylphenol polyethoxylates(APEO),and formaldehyde and methanol simultaneous determination were respectively developed by reaction-based headspace gas chromatography(HS-GC);(2)based on the GC signals change of water vapor on a set closed sample vials to determine fiber water-retaining capability,a new headspace gas chromatography method for the accurate determination of fiber water-retaining capability in raw materials of disposable hygiene products was developed;(3)based on tracer,a new headspace gas chromatography method for determining the swelling capacity of superabsorbent polymers in raw materials of disposable hygiene products was developed.On the other hand,the work based on ultraviolet-visible(UV/Vis)spectroscopy,(1)the spectral absorption contributed by the leached lignin in the extraction medium can be effectively subtracted through dual-wavelength spectroscopy,a new method for more accurate determination of migratable fluorescent whitening agents(FWA)in disposable hygiene products was developed;(2)the spectral errors caused by baseline drafting and light scattering due to the instability of spectrophotometer can be subtracted through dual-wavelength spectroscopy for determining lower amount of free formaldehyde in disposable hygiene products,so the accuracy and sensitivity for formaldehyde analysis were improved significantly;(3)using internal standard method with UV/Vis,a new method for rapidly determining bactericide-benzethonium chloride in disposable hygiene products was developed;(4)the results showed that: based on kinetic UV/Vis method,UV/Vis on-line monitoring system was established and blue dextran 2000 of high molecular weight was used as tracer,so the swelling behavior of SAP during the process can be monitored;a semi-empirical model for predicting the swelling behavior of superabsorbent polymers was developed in consideration of effect of external swelling solution conditions(temperature,p H and salt concentration)on swelling behavior.Compared with traditional methods,the above methods have advantages of easy operation,high efficiency,better reproducibility and accuracy,etc.,which support quality tests and safety evaluation for disposable hygiene products.Meanwhile it can provide important theory basis and instruction for improving disposable hygiene products according to product design and optimizing manufacture of SAP.