Plasma Formation and Its Parameters Used in Calibration-Free Laser-Induced Breakdown Spectroscopy

A rapidly developing technique over the last two years is laser induced break-down spectroscopy (LIBS), also known as laser-induced plasma spectroscopy (LIPS), a non-destructive spectroscopy technique that is mostly used for the analytical study of samples. With this technique, multiple elemental composition of elements are analyzed simultaneously without considering the form of sample that may be solid, liquid, or gas. Moreover, economically it is a very beneficial and valuable technique because no sample preparation is required, and sample consumption is very small. This technique is powerful enough that it can bore a microscopic crater usually in the solid samples to target. This technique has great sensitivity to find the resolution down to a single grain. It has a variety of applications in the field of science such as archeology, soils, environmental protection, and so on.

Sensing Technology for Fish Freshness and Safety: A Review

Standard analytical methods for fish freshness assessment are based on the measurement of chemical and physical attributes related to fish appearance, color, meat elasticity or texture, odor, and taste. These methods have plenty of disadvantages, such as being destructive, expensive, and time consuming. All these techniques require highly skilled operators. In the last decade, rapid advances in the development of novel techniques for evaluating food quality attributes have led to the development of non-invasive and non-destructive instrumental techniques, such as biosensors, e-sensors, and spectroscopic methods. The available scientific reports demonstrate that all these new techniques provide a great deal of information with only one test, making them suitable for on-line and/or at-line process control. Moreover, these techniques often require little or no sample preparation and allow sample destruction to be avoided.

The Application of NMR Spectroscopy and Chemometrics in Authentication of Spices

Spices and herbs are among the most commonly adulterated food types. This is because spices are widely used to process food. Spices not only enhance the flavor and taste of food, but they are also sources of numerous bioactive compounds that are significantly beneficial for health. The healing effects of spices are connected with their antimicrobial, anti-inflammatory and carminative properties. However, regular consumption of adulterated spices may cause fatal damage to our system because adulterants in most cases are unhealthy. For that reason, the appropriate analytical methods are necessary for quality assurance and to ensure the authenticity of spices. Spectroscopic methods are gaining interest as they are fast, require little or no sample preparation, and provide rich structural information. This review provides an overview of the application of NMR spectroscopy combined with chemometric analysis to determine the quality and adulteration of spices.

Green Approaches to Sample Preparation Based on Extraction Techniques

Preparing a sample for analysis is a crucial step of many analytical procedures. The goal of sample preparation is to provide a representative, homogenous sample that is free of interferences and compatible with the intended analytical method. Green approaches to sample preparation require that the consumption of hazardous organic solvents and energy be minimized or even eliminated in the analytical process. While no sample preparation is clearly the most environmentally friendly approach, complete elimination of this step is not always practical. In such cases, the extraction techniques which use low amounts of solvents or no solvents are considered ideal alternatives. This paper presents an overview of green extraction procedures and sample preparation methodologies, briefly introduces their theoretical principles, and describes the recent developments in food, pharmaceutical, environmental and bioanalytical chemistry applications.

Case Studies on Application of Electro Optical Probing (EOP) - A Noninvasive Backside Localization Technique in Failure Analysis

Given the challenges FA Engineers have in fault localization, top-side analysis is facing a major challenge with today’s advanced packaging and shrinking of die sizes. At wafer and die level it is relatively easy to probe with little or no sample preparation. Greater challenges occur after the die is packaged. The difficulty further lies in non-destructively analyzing the die. Another issue with failure analysis is accurately deprocessing the device for probe pad deposition. Techniques like Electro Optical Probing (EOP) or Laser Voltage Probing (LVP) acquire electrical signals on transistors and create an activity map of the circuitry. In failure analysis, it is applied to localize defects. This paper discusses integrating EOP techniques in traditional FA to localize failure in mixed signal ICs. Three case studies were presented in this paper to establish the technique to be effective, quick and easy to probe non-invasively with minimal backside sample preparation.

Voltammetric Determination of Anethole on La2O3/CPE and BDDE

In this work, DPV determination of anethole was presented using various carbon, two-diameter (1.5 and 3 mm) electrodes, that is, BDD, GC, CP, and CP doped by La2O3 and CeO2 nanoparticles. La2O3/CPE to our best knowledge was proposed first time. Cyclic voltammograms confirmed totally irreversible electrode electrooxidation process, controlled by diffusion, in which two electrons take part. The most satisfactory sensitivity 0.885 ± 0.016 µA/mg L−1 in 0.1 mol L−1 acetate buffer was obtained for La2O3/CPE with the correlation coefficient r of 0.9993, while for BDDE it was 0.135 ± 0.003 µA/mg L−1 with r of 0.9990. The lowest detection limit of 0.004 mg L−1 was reached on La2O3/CPE (3 mm), what may be compared with the most sensitive conjugate methods, but in the proposed approach, no sample preparation and analyte separation was needed. Anethole was successfully determined in specially prepared ethanol extracts of herbal mixtures of various compositions, which imitated real products. The proposed procedure was verified in analysis of commercial products, that is, anise essential oil, which contains a large concentration of anethole, and in alcohol drinks like Metaxa, Ouzo, and Rakija, in which the considered analyte occurs on trace levels. Structure and properties of the considered nanopowders and graphite pastes were investigated by EDX, SEM, and EIS.

Trends in Microextraction Techniques for Sample Preparation

Although analytical scientists equivocally agree that “no sample preparation” would be the best approach, the fact is that all samples that are handled in any analytical laboratory need to undergo treatment to some extent prior to their introduction to the analytical instrument [...]

Характеристика сучасних методів визначення сирого протеїну у кормах та рослинній сировині

Todays in laboratory and manufacturing practice of veterinary medicine of Ukraine, for the detertimations of raw protein in feed and in plant raw are used as classic and as modern methods depending from the aim and the task of research. Thats why the article describes the modern methods of the determination of content of nitrogen and the calculation of raw protein in feeds for animals and in plant materials, in particular, photometric, classical – Kjeldahl method, modern – Dumas and spectrometric methods (the method of infrared spectrometry in the near range (NIR-spectrometry). Despite of the facts, that the Kjeldahl method remains generally accepted in the determination of the protein and is most often used in research, but the modern methods – the Dumas method and NIR-spectrometry are widely adopted in laboratory practice. The main advantage of these methods is the speed of the analysis (the one definition takes only a few minutes), practically there is no sample preparation, and the most important is that the toxic chemicals and catalysts are not used.Thus, despite the fact that the Kjeldahl method remains generally accepted in the determination of the protein, and it is most frequently used in research, but modern methods, the Dumas method and NIR-spectrometry, are widely implemented in laboratory practice. The main advantage of these methods is the speed of conducting the analysis (one definition only takes a few minutes), there is practically no sample preparation, and most importantly, toxic chemicals and catalysts are not used.

Retracted Article: Novel techniques for enhancing the performance of support vector regression chemo-metric in quantitative analysis of LIBS spectra

Laser induced breakdown spectroscopy (LIBS) is an atomic emission spectroscopy through which elemental compositions of materials can be determined with little or no sample preparation. Small sample requirement as well...