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In analytical chemistry, the use of the simplest tool that provides the possibility of on-site measurement, low cost, and simple equipment has always been an area of interest for researchers. In recent years, the use of smartphones as an available tool can have these features. In this study, Bi2O3/ZnO/Pd adsorbent was used for preconcentration and measurement of Sudan IV color as one of the azo family colors in food and water samples, exploiting ultrasonic-assisted dispersive micro solid phase extraction (UA-d-µ-SPE) method along with a smartphone. The structure of this adsorbent was examined by XRD, SEM, and EDS analyses. Factors such as the amount of adsorbent (5.1 mg), sample solution pH (7.1), washing solvent volume (430.0 µL), and adsorption time (65 seconds) were optimized, utilizing central composite design (CCD) method. The type of washing solvent (methanol) and desorption time (45 seconds) were also optimized using the oneparameter-at-a-time method. In the best conditions, the limit of detection (LOD) was 5.58 ng mL-1, and the linear detection range (LDR) for this color was 20-1100 ng mL-1. The enrichment factor (EF) was also computed as 22.87. In addition, the relative standard deviation (RSD%) was acquired as 3.91 with n=5. [ABSTRACT FROM AUTHOR]

AbstractHollow fiber liquid-phase microextraction is commonly used in analytical chemistry, providing high clean-up and pre-concentration factors. However, a major issue with this method is the long extraction time. The objective of this project is to reduce the extraction time by inducing different types of fluid motion in the sample solution. Three methods were employed: agitation using a magnetic stir bar in the horizontal position (conventional method), utilization of an air pump, and agitation using a magnetic stir bar in the vertical position for the pre-concentration and determination of non-steroidal anti-inflammatory drugs (naproxen, ibuprofen, and mefenamic acid) in biological samples via high-performance liquid chromatography with ultraviolet absorbance detection. The results demonstrated a significant reduction in extraction time and limit of detection when the air pump was employed compared to the conventional method of stirring with a magnetic stir bar in the horizontal position. Moreover, the mentioned parameters were even lower when stirring solutions were accomplished using a vertically-positioned magnetic stir bar, surpassing the method utilizing the air pump for agitation. Furthermore, the relative standard deviations were also lower when a vertically-positioned magnetic stir bar was used compared to the conventional method with a horizontally-positioned magnetic stir bar, while those of the air pump-assisted agitation method fell between the values of the aforementioned methods. [ABSTRACT FROM AUTHOR]