Ultrasound-assisted matrix solid-phase dispersive liquid extraction for the determination of intermediates in hair dyes with ion chromatography

Determination of 11 Kinds of Hair Dyes in Hair-Dyeing Products by Liquid Chromatography-Tandem Mass Spectrometry

Eleven kinds of hair dyes were determined in hair-dyeing products by liquid chromatography-tandem mass spectrometry (MS). The samples were extracted with ultrasound in methanol for 20 min. After centrifugation, the supernatant was diluted with 10% methanol/90% water (v/v). Then, the solution was analyzed by Shim-pack Scepter C18-120 column (100 mm × 2.1 mm, 1.9 μm) plus electrospray ionization-MS/MS. Matrix-matched standard solutions were used to analyze the samples. The limits of detection were from 0.15 to 10 mg/kg, the limits of quantification were from 0.5 to 40 mg/kg and the recovery was from 79.4 to 109.2%. The protocol was selective and accurate and was satisfyingly applied to analyze hair dyes in different kinds of commercial products. 1-Hydroxyethyl-4,5-diaminopyrazole sulfate, hydroxyethyl-p-phenylenediamine sulfate, 2-methyl-5-hydroxyethylaminophenol, 5-amino-6-chloro-o-cresol, 3-nitro-p-hydroxyethylaminophenol and 2-amino-6-chloro-4-nitrophenol were detected in 10 samples with the concentrations between limits of detection and quantification to 9.27 × 104 mg/kg.

Decoding Cosmetic Complexities: A Comprehensive Guide to Matrix Composition and Pretreatment Technology

Despite advancements in analytical technologies, the complex nature of cosmetic matrices, coupled with the presence of diverse and trace unauthorized additives, hinders the application of these technologies in cosmetics analysis. This not only impedes effective regulation of cosmetics but also leads to the continual infiltration of illegal products into the market, posing serious health risks to consumers. The establishment of cosmetic regulations is often based on extensive scientific experiments, resulting in a certain degree of latency. Therefore, timely advancement in laboratory research is crucial to ensure the timely update and adaptability of regulations. A comprehensive understanding of the composition of cosmetic matrices and their pretreatment technologies is vital for enhancing the efficiency and accuracy of cosmetic detection. Drawing upon the China National Medical Products Administration's 2021 Cosmetic Classification Rules and Classification Catalogue, we streamline the wide array of cosmetics into four principal categories based on the following compositions: emulsified, liquid, powdered, and wax-based cosmetics. In this review, the characteristics, compositional elements, and physicochemical properties inherent to each category, as well as an extensive overview of the evolution of pretreatment methods for different categories, will be explored. Our objective is to provide a clear and comprehensive guide, equipping researchers with profound insights into the core compositions and pretreatment methods of cosmetics, which will in turn advance cosmetic analysis and improve detection and regulatory approaches in the industry.

Optimization of the interaction of graphene quantum dots with lipase for biological applications

Graphene quantum dots (GQDs) are known as emerging sub-10 nm nanoparticles (NPs), which are in fact few-layered pieces of graphene, capable of emitting blue fluorescence, when exposed to 360 nm UV light. Understanding the details of the interaction between GQDs and lipase can serve as a critical step for improving the biological outcome of GQD-derived drug-delivery and diagnosis systems. The interaction occurs in the form of surface adsorption, which can subsequently influence the physicochemical properties of both the NP and the protein. Hence, a systematic approach was taken here to optimize the GQDs' synthesis conditions in order to achieve the highest possible quantum yield (QY). Furthermore, to understands the influence of the interaction of GQDs and lipase, on both the activity of lipase and the emission intensity of GQDs, various incubation conditions were tested to achieve optimized conditions over central composite design algorithm by Design-Expert®, using response surface methodology. The results show that the GQDs fabricated by thermal decomposition of citric acid at 160°C, with a heating duration of 55 min, obtain almost three times higher QY than the highest values reported previously. The best enzymatic activity after the formation of the hard corona, as well as the highest fluorescent emission, were achieved at GQD-to-enzyme ratios within the rage of 23-25%, at temperatures between 41 and 42°C, for 6-8 min. In the aforementioned condition, the enzyme retains 91-95% of its activity and the NP preserves about 80-82% of its fluorescence intensity after incubation.

Optimization of process parameters for determination of trace Hazardous dyes from industrial wastewaters based on nanostructures materials under ultrasound energy

In this study, ultrasound-assisted dispersive solid phase micro-extraction based on nanosorbent namely silver-zinc oxide nanoparticles loaded on activated carbon (Ag-ZnO-NP-AC) combined with derivative spectrophotometry method for the simultaneous pre-concentration and determination of Methyl Green (MG) and Rose Bengal (RB) dyes in water and industrial wastewater. Characterized sorbent by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), particle-size distribution (PSD), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and Transmission electron microscopy (TEM) analysis with superior adsorption capacity was applied in ultrasound assisted dispersive-solid-phase micro-extraction (UA-DSPME) methodology. pH, sorbent mass, ultrasonication time, and eluent volume influence and contribution on response correspond to simultaneous pre-concentration and determination of MG and RB were optimized by response surface methodology (RSM) and results were compared with the experimental values. Under the optimal conditions (UA-DSPME), the enrichment factors (EFs) were 93.89 and 97.33 for the MG and RB dyes, respectively. The limits of detection were 2.14 and 2.73ngmL^-1 and the limit of quantification were 7.15 and 9.09ngmL^-1 for MG and RB, respectively. The analytes can be determined over 10-2000ngmL^-1 with recoveries between 90.8% to 97.7% and RSDs less than 3.6%. The developed method due to simplicity and rapidity is able successful for repeatable and accurate monitoring of under study analytes from complicated matrices.

Green effervescence assisted dispersive liquid–liquid microextraction based on a hydrophobic deep eutectic solvent for determination of Sunset Yellow and Brilliant Blue FCF in food samples

In this study, a simple, fast and sensitive method called effervescence assisted dispersive liquid–liquid microextraction based on a hydrophobic deep eutectic solvent (EADLLME-DES) was used to extract synthetic dyes from food samples.

Ultrasound assisted extraction of Maxilon Red GRL dye from water samples using cobalt ferrite nanoparticles loaded on activated carbon as sorbent: Optimization and modeling

In this research, a selective, simple and rapid ultrasound assisted dispersive solid-phase micro-microextraction (UA-DSPME) was developed using cobalt ferrite nanoparticles loaded on activated carbon (CoFe₂O₄-NPs-AC) as an efficient sorbent for the preconcentration and determination of Maxilon Red GRL (MR-GRL) dye. The properties of sorbent are characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Vibrating sample magnetometers (VSM), Fourier transform infrared spectroscopy (FTIR), Particle size distribution (PSD) and Scanning Electron Microscope (SEM) techniques. The factors affecting on the determination of MR-GRL dye were investigated and optimized by central composite design (CCD) and artificial neural networks based on genetic algorithm (ANN-GA). CCD and ANN-GA were used for optimization. Using ANN-GA, optimum conditions were set at 6.70, 1.2mg, 5.5min and 174μL for pH, sorbent amount, sonication time and volume of eluent, respectively. Under the optimized conditions obtained from ANN-GA, the method exhibited a linear dynamic range of 30-3000ngmL^-1 with a detection limit of 5.70ngmL^-1. The preconcentration factor and enrichment factor were 57.47 and 93.54, respectively with relative standard deviations (RSDs) less than 4.0% (N=6). The interference effect of some ions and dyes was also investigated and the results show a good selectivity for this method. Finally, the method was successfully applied to the preconcentration and determination of Maxilon Red GRL in water and wastewater samples.

Ultrasonic assisted dispersive solid-phase microextraction of Eriochrome Cyanine R from water sample on ultrasonically synthesized lead (II) dioxide nanoparticles loaded on activated carbon: Experimental design methodology

The present research focus on designing an appropriate dispersive solid-phase microextraction (UA-DSPME) for preconcentration and determination of Eriochrome Cyanine R (ECR) in aqueous solutions with aid of sonication using lead (II) dioxide nanoparticles loaded on activated carbon (PbO-NPs-AC). This material was fully identified with XRD and SEM. Influence of pH, amounts of sorbent, type and volume of eluent, and sonication time on response properties were investigated and optimized by central composite design (CCD) combined with surface response methodology using STATISTICA. Among different solvents, dimethyl sulfoxide (DMSO) was selected as an efficient eluent, which its combination by present nanoparticles and application of ultrasound waves led to enhancement in mass transfer. The predicted maximum extraction (100%) under the optimum conditions of the process variables viz. pH 4.5, eluent 200μL, adsorbent dosage 2.5mg and 5min sonication was close to the experimental value (99.50%). at optimum conditions some experimental features like wide 5-2000ngmL^-1 ECR, low detection limit (0.43ngmL^-1, S/N=3:1) and good repeatability and reproducibility (relative standard deviation, <5.5%, n=12) indicate versatility in successful applicability of present method for real sample analysis. Investigation of accuracy by spiking known concentration of ECR over 200-600ngmL^-1 gave mean recoveries from 94.850% to 101.42% under optimal conditions. The procedure was also applied for the pre-concentration and subsequent determination of ECR in tap and waste waters.

Current trends in sample preparation for cosmetic analysis

The widespread applications of cosmetics in modern life make their analysis particularly important from a safety point of view. There is a wide variety of restricted ingredients and prohibited substances that primarily influence the safety of cosmetics. Sample preparation for cosmetic analysis is a crucial step as the complex matrices may seriously interfere with the determination of target analytes. In this review, some new developments (2010-2016) in sample preparation techniques for cosmetic analysis, including liquid-phase microextraction, solid-phase microextraction, matrix solid-phase dispersion, pressurized liquid extraction, cloud point extraction, ultrasound-assisted extraction, and microwave digestion, are presented. Furthermore, the research and progress in sample preparation techniques and their applications in the separation and purification of allowed ingredients and prohibited substances are reviewed.

Simultaneous determination of cationic dyes in water samples with dispersive liquid–liquid microextraction followed by spectrophotometry: experimental design methodology

Dispersive liquid–liquid microextraction (DLLME) combined with spectrophotometry was applied to the determination of two dyes in water samples.