Simultaneous spectrophotometric determination of crystal violet and malachite green in water samples using partial least squares regression and central composite design after preconcentration by dispersive solid-phase extraction

Abstract

In this paper, a simple, fast, and inexpensive method is introduced for the simultaneous spectrophotometric determination of crystal violet (CV) and malachite green (MG) contents in aquatic samples using partial least squares regression (PLS) as a multivariate calibration technique after preconcentration by graphene oxide (GO). The method was based on the sorption and desorption of analytes onto GO and direct determination by ultraviolet-visible spectrophotometric techniques. GO was synthesized according to Hummers method. To characterize the shape and structure of GO, FT-IR, SEM, and XRD were used. The effective factors on the extraction efficiency such as pH, extraction time, and the amount of adsorbent were optimized using central composite design. The optimum values of these factors were 6, 15 min, and 12 mg, respectively. The maximum capacity of GO for the adsorption of CV and MG was 63.17 and 77.02 mg g, respectively. Preconcentration factors and extraction recoveries were obtained and were 19.6, 98% for CV and 20, 100% for MG, respectively. LOD and linear dynamic ranges for CV and MG were 0.009, 0.03-0.3, 0.015, and 0.05-0.5 (μg mL), respectively. The intra-day and inter-day relative standard deviations were 1.99 and 0.58 for CV and 1.69 and 3.13 for MG at the concentration level of 50 ng mL, respectively. Finally, the proposed DSPE/PLS method was successfully applied for the simultaneous determination of the trace amount of CV and MG in the real water samples.

Electrochemical Sensor for Detection and Degradation Studies of Ethyl Violet Dye

“…The LOD of ethyl violet was found to be 0.36 nM, indicating that HOOC- f CNTs/GCE is a promising tool for trace level detection of targeted toxins. The calculated figures of merit especially the LOD value (0.36 nM) are far better than the reported LODs for the ethyl violet dye. − Table shows a comparison between the HOOC- f CNTs/GCE assay and other reported ethyl violet detection methods. Remarkably, the LOD for the target analyte attainable by using the stated platform is much better than reported methods.…”

Rapid ultrasound‐assisted dispersive solid‐phase extraction of nonsteroidal anti‐inflammatory drugs in urine using oleic acid functionalized magnetic graphene oxide

“…The data obtained were assessed by analysis of variance, which is shown in Supporting Information Table S3. A P ‐value less than 0.05 in the analysis of variance table demonstrates the statistical significance of a factor at 95% confidence level .…”

“…So, influence of the different eluents including methanol, ethanol, and acetonitrile on desorption yield was investigated. Desorption recovery was calculated by the following equation . where A and D are the moles of adsorbed and desorbed analytes, respectively (see the Supporting Information for more details).…”

“…So, influence of the different eluents including methanol, ethanol, and acetonitrile on desorption yield was investigated. Desorption recovery was calculated by the following equation [33].…”

Simultaneous Determination of Malachite Green, Chloramphenicols, Sulfonamides, and Fluoroquinolones Residues in Fish by Liquid Chromatography-Mass Spectrometry

“…Chloramphenicol, florfenicol, and malachite green are prohibited as aquaculture veterinary drugs in many countries including the United States, Canada, and China and in the European Union. However, these drug residues which settle in aquatic tissues can cause some adverse human health effects, such as allergic reactions and alterations in the delicate balance of intestinal flora, and they can produce resistance to antibiotics [8][9][10][11][12][13][14]. Malachite green and its metabolites are toxic, mutagenic, and carcinogenic.…”