高效液相色谱-蒸发光散射检测法同时测定口腔护理产品中10种季铵盐类杀菌剂OA北大核心CSTPCDMEDLINE

Quaternary ammonium salt bactericides are broad-spectrum bactericides often used in oral care products because of their high antibacterial efficacy,strong penetration,and low toxicity.However,the excessive use of quaternary ammonium salt bactericides may cause con-tact dermatitis,scalding poisoning,and even death.Existing methods to determine quaternary ammonium salt bactericides are unable to meet current requirements owing to the lack of deter-mination components.Therefore,establishing a simple and accurate method for the simultane-ous detection of more quaternary ammonium salt bactericides is necessary. In this study,a method that couples sample pretreatment with high performance liquid chro-matography-evaporative light-scattering detection(HPLC-ELSD)was developed for the simulta-neous determination of quaternary ammonium salt bactericides in oral care products,including dodecyltrimethylammonium chloride,dodecyldimethylbenzylammonium chloride,benzethoni-um chloride,tetradecyl trimethyl ammonium chloride,tetradecyldimethylbenzylammonium chloride,N-hexadecyltrimethylammonium chloride,benzyldimethylhexadecylammonium chlo-ride,trimethylstearylammonium chloride,stearyldimethylbenzylammonium chloride,and doco-syltrimethylammonium chloride.Some of these bactericides do not absorb ultraviolet light,so a universal evaporative light-scattering detector was used owing to testing cost and stability con-cerns.The paste samples contained thickening agents,which are highly soluble in water but in-soluble in organic solvents;these agents can seriously affect the results of sample pretreatment and damage the chromatographic column.Hence,sample dehydration was necessary.In this study,four dehydration methods were compared.Anhydrous sodium sulfate(Na2SO4)was se-lected,and the amount of Na2SO4 was optimized.Based on the solubility of the 10 target com-pounds and extraction efficiency,three extraction solvents were compared,and ethanol was selected.Ultrasonic extraction was the primary extraction process used in this study.The effects of different ultrasonication times,temperatures,and powers on the extraction recover-ies were also investigated.Ultimately,the optimized conditions were as follows:extraction of the dehydrated paste and powder samples using ethanol at room temperature(25 ℃)for 20 min under 100 W ultrasound power,and dilution of the liquid sample with ethanol. After extraction,the samples were separated on an Acclaim Surfactant column(150 mm×4.6 mm,5 μm)with 50 mmol/L ammonium acetate aqueous solution(pH=5.5)(A)and acetoni-trile(B)as mobile phases.The gradient elution program were as follows:0-5.0 min,75％A-35％A,5.0-15.0 min,35％A-20％A,15.0-20.0 min,20％A,20.0-21.0 min,20％A-75％A,21.0-25.0 min,75％A.An external standard method was used for quantitative determination.The 10 compounds were analyzed within 25 min.Linear equations,correlation coefficients,and linear ranges were obtained by analyzing a series of mixed standard working solutions.The lim-its of detection(LODs,S/N=3)and quantification(LOQs,S/N=10)of the 10 components were determined.Stearyldimethylbenzylammonium chloride and docosyltrimethylammonium chloride showed good linear relationships in the range of 10-200 mg/L,while the other com-pounds demonstrated good linear relationships in the range of 5-100 mg/L.In all cases,corre-lation coefficients(R2)of no less than 0.999 2 were obtained.The LODs and LOQs were in the range of 1.42-3.31 mg/L and 4.25-9.94 mg/L,respectively.Ten analytes were spiked in blank matrices,such as toothpaste(paste),mouthwash(liquid),and dentifrice powder(powder)at three levels,and the recoveries and precisions were calculated.The average recoveries were 87.9％-103.1％,and the corresponding relative standard deviations(RSDs)did not exceed 5.5％(n=6).The developed method was used to detect 109 oral care products.Benzyldimeth-ylhexadecylammonium chloride and stearyldimethylbenzylammonium chloride revealed high de-tection rates.Moreover,the amount of stearyldimethylbenzylammonium chloride in one tooth-paste sample exceeded regulatory requirements.Given its advantages of good precision and ac-curacy,the developed method is suitable for the quantitative analysis of the 10 aforementioned compounds in typical oral care products.The study findings can serve as a reference for the quality and safety monitoring of oral care products.