季铵盐类杀菌剂是口腔护理产品中常用的广谱杀菌剂,因其抗菌效率高,穿透力强,和低毒性。然而,过量使用季铵盐杀菌剂可能导致接触性皮炎,烫伤中毒,甚至死亡。现有的测定季铵盐杀菌剂的方法由于缺乏测定成分而无法满足当前的要求。因此,建立一种简单、准确的同时检测多季铵盐杀菌剂的方法是必要的。在这项研究中,建立了一种将样品前处理与高效液相色谱-蒸发光散射检测(HPLC-ELSD)相结合的方法,用于同时测定口腔护理产品中的季铵盐杀菌剂。包括十二烷基三甲基氯化铵,十二烷基二甲基苄基氯化铵,苄索氯铵,十四烷基三甲基氯化铵,十四烷基二甲基苄基氯化铵,N-十六烷基三甲基氯化铵,苄基二甲基十六烷基氯化铵,三甲基硬脂酰氯化铵,硬脂基二甲基苄基氯化铵,和二十二烷基三甲基氯化铵.其中一些杀菌剂不吸收紫外线,因此,由于测试成本和稳定性问题,使用了通用的蒸发光散射检测器。糊状样品含有增稠剂,它们高度溶于水,但不溶于有机溶剂;这些试剂会严重影响样品预处理的结果并损坏色谱柱。因此,样品脱水是必要的。在这项研究中,比较了四种脱水方法。选择无水硫酸钠(Na2SO4),优化了Na2SO4的用量。根据10种目标化合物的溶解度和提取效率,比较了三种萃取溶剂,选择乙醇。超声波提取是本研究的主要提取工艺。不同超声处理时间的影响,温度,并对萃取回收率进行了研究。最终,优化条件如下:在室温(25℃)下,在100W超声功率下,用乙醇提取脱水的糊状和粉末样品20min,用乙醇稀释液体样品。提取后,样品在Acclaim表面活性剂色谱柱上分离(150mm×4.6mm,5μm),以50mmol/L乙酸铵水溶液(pH=5.5)(A)和乙腈(B)为流动相。梯度洗脱程序如下:0-5.0分钟,75%A-35%A,5.0-15.0分钟,35%A-20%A,15.0-20.0分钟,20%A,20.0-21.0分钟,20%A-75%A,21.0-25.0分钟,75%A.使用外标法进行定量测定。在25分钟内分析10种化合物。线性方程组,相关系数,通过分析一系列混合标准工作溶液,获得线性范围。检测限(LODs,S/N=3)和量化(LOQs,测定10个组分的S/N=10)。硬脂基二甲基苄基氯化铵和十二烷基三甲基氯化铵在10-200mg/L范围内呈良好的线性关系,而其他化合物在5-100mg/L范围内表现出良好的线性关系。在所有情况下,相关系数(R2)不小于0.9992。LOD和LOQ在1.42-3.31mg/L和4.25-9.94mg/L的范围内,分别。将十种分析物掺入空白基质中,如牙膏(糊),漱口水(液体),和三个级别的洁齿剂粉末(粉末),并计算了回收率和精密度。平均回收率为87.9%-103.1%,相应的相对标准偏差(RSD)不超过5.5%(n=6)。所开发的方法用于检测109种口腔护理产品。苄基二甲基十六烷基氯化铵和硬脂基二甲基苄基氯化铵的检出率高。此外,一个牙膏样品中的硬脂基二甲基苄基氯化铵的含量超过了法规要求。鉴于其良好的精度和准确性的优点,该方法适用于典型口腔护理产品中上述化合物的定量分析。研究结果可为口腔护理产品的质量和安全监测提供参考。
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 contact 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 determination components. Therefore, establishing a simple and accurate method for the simultaneous detection of more quaternary ammonium salt bactericides is necessary. In this study, a method that couples sample pretreatment with high performance liquid chromatography-evaporative light-scattering detection (HPLC-ELSD) was developed for the simultaneous determination of quaternary ammonium salt bactericides in oral care products, including dodecyltrimethylammonium chloride, dodecyldimethylbenzylammonium chloride, benzethonium chloride, tetradecyl trimethyl ammonium chloride, tetradecyldimethylbenzylammonium chloride, N-hexadecyltrimethylammonium chloride, benzyldimethylhexadecylammonium chloride, trimethylstearylammonium chloride, stearyldimethylbenzylammonium chloride, and docosyltrimethylammonium 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 concerns. The paste samples contained thickening agents, which are highly soluble in water but insoluble 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 selected, and the amount of Na2SO4 was optimized. Based on the solubility of the 10 target compounds 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 recoveries 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 acetonitrile (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 limits 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 compounds demonstrated good linear relationships in the range of 5-100 mg/L. In all cases, correlation coefficients (R2) of no less than 0.9992 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. Benzyldimethylhexadecylammonium chloride and stearyldimethylbenzylammonium chloride revealed high detection rates. Moreover, the amount of stearyldimethylbenzylammonium chloride in one toothpaste sample exceeded regulatory requirements. Given its advantages of good precision and accuracy, 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.