Determination of Diphenylamine Residue in Fruit Samples Using Dispersive Liquid-Liquid Microextraction Coupled with Ion Mobility Spectrometry

In this study, a simple, fast, and inexpensive method is introduced to extract and determine remaining diphenylamine (DPA) in fruit samples by the combination of Dispersive Liquid-Liquid MicroExtraction (DLLME) and Ion Mobility Spectrometry (IMS). The main parameters such as the type and volume of extraction solvent, volume of dispersive solvent, salt addition, centrifugation time, and sample pH that affected the extraction efficiency were evaluated by performing single-factor variable experiments. Chlorobenzene was selected as the extraction solvent, which was dispersed into samples with methanol as the dispersive solvent. In the optimized experimental conditions, the suggested technique showed good linearity in the range of 25-550 µg/L with a correlation coefficient (R2) 0.997. The detection limits were obtained based on S/N of 3 as 7.5 µg/L in the standard solution and 17µg/kg in apple and pear samples. The repeatability and reproducibility of the method expressed as intraday (n=5) and interday (n=3) relative standard deviations were 6.0 and 7.5%, respectively at a concentration level of 150 µg/L DPA, and the enrichment factor was 36.0. Analysis of fruit samples for measurement of DPA showed that the introduced method has great potential to extract and determine the DPA in real samples.