A portable and simple microextractor device was constructed by aligning six miniaturized multi-stir-rod microextractors. Each microextractor was prepared from rod-like multiwalled carbon nanotubes functionalized with a carboxylic group (MWCNTs-COOH) in composite monoliths that were bundled together and connected to a small DC motor. Using six of these microextractors, the device could extract six samples at the same time. A scanning electron microscope (SEM) showed the MWCNTs-COOH well distributed throughout the highly porous structure of the monolith-MWCNTs-COOH-stir-rod. This miniaturized multi-stir-rod microextractor device was used for the extraction of four parabens, methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP). Under optimized conditions, good linearities were obtained in the concentration range of 1.0 ng mL⁻¹ to 1.0 µg mL⁻¹ for MP and EP and 2.0 ng mL⁻¹ to 1.0 µg mL⁻¹ for PP and BP. The limits of detection were low, 636.2 ± 7.6 pg mL⁻¹ for MP, 675.5 ± 6.0 pg mL⁻¹ for EP, 676.6 ± 8.6 pg mL⁻¹ for PP and 803.4 ± 9.6 pg mL⁻¹ for BP. The developed microextractor could be used up to 15 times (%RSDs from 1.5 to 5.2) and also provided good preparation reproducibility (%RSD from 1.3 to 5.8, n = 6). The % RSDs of intra-day (n = 6) and inter-day (n = 6) precisions were obtained from 1.10–7.79 and 1.96–7.55, respectively. This developed device coupled with high performance liquid chromatography-diode array detector (HPLC-DAD) was applied for the extraction and preconcentration of four parabens in personal care products and cosmetics. The recoveries were studied by spiking the standard solution of parabens in real samples. Good recoveries were obtained in the range of 89.0 ± 2.7 to 102.7 ± 1.8% for MP, 88.09 ± 6.4 to 102.5 ± 1.0% for EP, 83.4 ± 6.4 to 102.9 ± 1.5% for PP and 83.5 ± 3.6 to 102.3 ± 2.0% for BP. This developed device might be easily applied for the extraction and preconcentration of other trace organic compounds in sample matrices.

通过对准六个小型化的多搅拌杆微萃取器，构造了一种便携式且简单的微萃取器装置。每个微萃取器均由棒状多壁碳纳米管制成，这些碳纳米管在复合整料中被羧基官能团（MWCNTs-COOH）官能化，该整料捆绑在一起并连接至小型DC电动机。使用这些微型提取器中的六个，该设备可以同时提取六个样品。扫描电子显微镜（SEM）显示，MWCNTs-COOH很好地分布在整料-MWCNTs-COOH-搅拌棒的高度多孔结构中。该微型多杆微萃取器设备用于提取四种对羟基苯甲酸酯，对羟基苯甲酸甲酯（MP），对羟基苯甲酸乙酯（EP），对羟基苯甲酸丙酯（PP）和对羟基苯甲酸丁酯（BP）。在优化的条件下，在1.0 ng mL的浓度范围内获得了良好的线性^-1至1.0微克毫升^-1为MP和EP和2.0纳克毫升^-1至1.0微克毫升^-1为PP和BP。检测限为低，636.2±7.6皮克毫升^-1为MP，675.5±6.0皮克毫升^-1对于EP，676.6±8.6皮克毫升^-1为PP和803.4±9.6皮克毫升^-1对于BP。开发的微萃取器最多可使用15次（％RSD从1.5到5.2），并且还提供了良好的制剂重现性（％RSD从1.3到5.8，n = 6）。日内（n = 6）和日间（n = 6）精度的％RSDs分别从1.10-7.79和1.96-7.55获得。该开发的装置与高效液相色谱-二极管阵列检测器（HPLC-DAD）结合在一起，可用于个人护理产品和化妆品中四种对羟基苯甲酸酯的提取和预浓缩。通过加标实际样品中对羟基苯甲酸酯的标准溶液来研究回收率。回收率在MP的89.0±2.7至102.7±1.8％，EP在88.09±6.4至102.5±1.0％，PP在83.4±6.4至102.9±1.5％，PP在83.5±3.6至102.3±2.0％的范围内BP。