Capillary Electrophoresis System Research Articles

Characterization of variably protease-sensitive prionopathy by capillary electrophoresis.

Variably Protease Sensitive Prionopathy (VPSPr) is a rare human prion disease that, like Creutzfeldt-Jakob disease (CJD), results in the deposition of abnormally folded prion protein aggregates in the brain and is ultimately fatal. Neuropathology and clinical features of VPSPr are heterogeneous. However, the key discriminating feature is the relative sensitivity of the pathological prion protein to proteinase digestion compared to that typically seen in other human prion cases. Three major fragments of 23, 17 and 7kDa are characteristic of the disease following digestion with proteinase K. We recently reported the utility of the highly adaptive and reproducible ProteinSimple™ capillary electrophoresis (CE) system to perform protein separation of PK digested prion protein in CJD. Consequently, we explored capillary-based electrophoresis (CE) technology as a sensitive method to detect and characterize VPSPr in a cohort of 29 cases. The unique 7kDa fragment has high intensity, particularly in cases with the codon 129 VV genotype, but can be missed by regular Western blotting due to the small size. However, this fragment is readily detected by CE in all cases. In addition, the flexibility of CE produced highly reproducible, semi-quantitative data for determining relative proteinase K sensitivity and epitope mapping of representative cases from each codon 129 genotype (VV, MV and MM).

Separation of tolperisone and its degradation products by a dual cyclodextrin capillary electrophoresis system to study their potential role in allergic events

Tolperisone is a centrally acting muscle relaxant that has been used for the treatment of post-stroke spasticity and low back pain. Recently, the safety of tolperisone pharmaceutical products has been reassessed due to growing concerns over allergic adverse events. Reactive degradants of tolperisone may be responsible for these hypersensitivity reactions. By forming adducts with proteins, they may act as haptens that could evoke allergic reactions. The objective of this study was to examine the presence of these degradants in tolperisone pharmaceutical products and to assess their reactivity to elucidate their possible role in the pro-allergic effect of tolperisone. For this purpose, capillary electrophoresis UV detection (CE-UV) method was developed and validated for the quantification of degradants. A dual cyclodextrin system was applied to achieve the appropriate migration order enabling the analysis of 2-methyl-1-(4-methylphenyl)prop-2-en-1-one (MMP) and 1-(4-methylphenyl)propan-1-one (MMPO) in the presence of high concentrations of tolperisone. MMP was identified as the main degradant in forced degradation tests of the active pharmaceutical ingredient. Differences in MMP content of tolperisone products by different manufacturers have also been found, highlighting the role of formulation in their stability. High reactivity of MMP was demonstrated as rapid and almost complete adduct formation with cysteine was found. This degradant thus might be responsible for the allergic adverse effects of tolperisone even when it is present in trace amounts in tablets by readily reacting with proteins in vivo.

Improving the technology of creating gluten-free bakery products based on compound flours

The article provides for the development of a gluten-free bread recipe, studying the quality indicators of composite flours from various cereals in order to update and improve the technology of gluten-free bakery products. Several alternatives have been proposed for this purpose. They demonstrated methods for obtaining the finished product using the composite addition of flour from various cereals that do not contain or have a very low gluten content, as well as using various technological treatments. It is devoted to the nutrition of patients with gluten intolerance, expansion and development of the range of bakery products from rice, buckwheat, corn flour in order to increase the adequacy of treatment, improve the quality of life of the patient and family. Production and consumption of such products - when choosing the most suitable assortment for this category of patients, it is considered important to germinate special types of necessary bread from them. For this purpose, grain crops grown in Kazakhstan were obtained -rice, buckwheat, corn flour. In addition, the studies reviewed the usefulness for the human body of the percentages of the necessary substances in the physico-chemical composition of buckwheat, corn and rice flour for patients with celiac disease. This information is also used in further research to develop special gluten-free bakery products with composite flour. In the process of making bread, 4 samples were taken. When determining the amino acid content in finished gluten-free bakery products, the capillary electrophoresis system "Kapel-105" was used. M-04-38-2009 investigated using methodology. The general patterns of changes in the nutritional value of the new gluten-free product were studied, as well as experimental baking works were carried out. Baking works were carried out experimentally, as a result of which it was found that sample No. 3 meets the requirements for gluten-free bread. The resulting samples are uniform in color, the surface color is brown, the softness of the bread is elastic, soft, porous, without foreign odors and the taste harmoniously matches the gluten[1]free bread product.

Capillary zone electrophoresis-tandem mass spectrometry for in-depth proteomics analysis via data-independent acquisition.

A capillary zone electrophoresis (CZE) system was coupled to an Orbitrap mass spectrometer operating in a data-independent acquisition (DIA) mode for in-depth proteomics analysis. The performance of this CZE-DIA-MS system was systemically evaluated and optimized under different operating conditions. The performance of the fully optimized CZE-DIA-MS system was subsequently compared to the one by using the same CZE-MS system operating in a data-dependent acquisition (DDA) mode. The experimental results show that the numbers of identified peptides and proteins acquired in the DIA mode are much higher than the ones acquired in the DDA mode, especially with the small sample loading amount. Specifically, the numbers of identified peptides and proteins acquired in the DIA mode are 1.8-fold and 2-fold higher than the ones acquired in the DDA mode by using 12.5 ng Hela digests. The proteins identified in the DIA mode also cover almost all the proteins identified in the DDA mode. In addition, a potential cancer biomarker protein, carbohydrate antigen 125, undetected in the DDA mode, can be easily identified in the DIA mode even with 12.5 ng Hela digests. The performance of the CZE-DIA-MS system for in-depth proteomics analysis with a limited sample amount has been fully demonstrated for the first time through this study.

Novel Insights into Hb Shaare Zedek Associated with β0-Thalassemia: Molecular Characteristics, Genetic Origin and Diagnostic Approaches.

Hemoglobin Shaare Zedek (Hb SZ) is a rare structural α-Hb variant. Characterizing its genotype-phenotype relationship and genetic origin enhances diagnostic and clinical management insights. We studied a proband and six family members using high-performance liquid chromatography (HPLC), capillary electrophoresis (CE), PCR, and sequencing to analyze α- and β-globin genes and α-globin haplotypes. Pathogenicity predictions and a rapid diagnostic method were developed. The proband, his father, grandfather, and aunt had Hb migrating to the HbH-zone on CE and elevated fetal hemoglobin (HbF) on HPLC. Direct sequencing identified an A to G mutation at codon 56 of the α2-globin gene, characteristic of Hb SZ. Additionally, the proband carried a β-globin gene mutation [HBB.52A>T]. Mild thalassemia-like changes were observed in the proband, whereas individuals with only the Hb SZ variant did not exhibit these changes. Pathogenicity predictions indicated that Hb SZ is benign. The variant can be identified using restriction fragment length polymorphism (RFLP) and allele-specific PCR. The Thai variant of Hb SZ is associated with the haplotype [- - M - - - -]. Hb SZ is a non-pathological variant that minimally affects red blood cell parameters, even when it coexists with β0-thalassemia. HPLC and CE systems cannot distinguish it from other Hbs, necessitating DNA analysis for accurate diagnosis.

Биологически ценные компоненты в сухих винах, изготовленных из винограда, культивируемого в Дагестане

Abstract. To expand the production of high-quality wines in Russia, it is necessary to use the varietal composition of grape raw materials, focusing on the indicators of the biochemical composition of local and introduced varieties, well adapted to the environmental conditions of terroirs. Viticulture is the leading branch of the agro-industrial complex of the Republic of Dagestan, which is one of the main producers of grapes and their processed products in the Russian Federation. The production of natural wines from local grape raw materials contributes to the growth of the economy and the prestige of Dagestan viticulture and winemaking. Therefore, the study of chemical parameters, including the vitamin composition and aroma-forming substances of experimental samples of dry white wines from grapes of introduced varieties Pervenets Magaracha, Rkatsiteli and varieties of local breeding Narma grown in Dagestan, is relevant. Standard research methods applied in enochemistry were used. The mass concentrations of vitamins and vitamin-like substances, phenolic compounds were determined using the capillary electrophoresis system "Kapel 104T", RF, NPF LUMEX, aroma-forming compounds – gas chromatograph "Crystal 2000M" (RF). Organoleptic ratings of Dagestan wines made in laboratory conditions – 7,5-7,8 points. Wine from the Narma variety excelled in the content of ascorbic acid – 18,93, orotic acid – 2,29 and coffee acid – 7,61 mg/dm3 . The highest total concentration of aromatic substances was determined in wine from the Pervenets Magaracha variety – 2178,30 mg/dm3 , and in wines from the Narma and Rkatsiteli varieties it was 743,29 and 777,81 mg/dm3 , respectively. Wine from Narma grapes has advantages in terms of the content of biologically active substances, and from the Pervenets of Magaracha – in terms of the number of aromatic compounds. Keywords: grapes, dry wine, vitamins, aroma-forming substances

Miniaturized green capillary electrophoresis system for the simultaneous analysis of Linagliptin and cefiximein in plasma

A novel combination therapy, consisting of the antidiabetic drug linagliptin (LIN) and the third-generation cephalosporin antibiotic cefixime (CEF), has recently been introduced to combat infections in diabetic patients. However, there is no published method for their in-vivo simultaneous determination in clinical biological specimens to support their pharmacokinetics and therapeutic monitoring. This study focuses on the development of a miniaturized capillary electrophoresis system-assisted with photodiode array detection (CE-PDA) for the simultaneous determination of LIN and CEF in clinical settings for analysis of plasma samples containing LIN and CEF. The conditions of electrophoretic separation of LIN, CEF, and Ibuprofen (as an internal standard), and the analysis procedures were successfully established. The linear range of the CE-PDA method was determined to be 0.5–100 µg mL−1 for LIN and 1–100 µg mL−1 for CEF. The CE-PDA approach exhibited high sensitivity, with limits of quantitation of 0.9 µg mL−1 for LIN and 1.2 µg mL−1 for CEF. In addition, the CE-PDA system was validated, and subsequently applied to real plasma samples withdrawn from rats received concurrent administration of LIN and CEF. The plasma protein was precipitated by acetonitrile. The miniaturized features of the system and its environmental impact were confirmed using three different metric tools. Additionally, the proposed CE-PDA system proved to be time-saving and cost-effective, making it highly suitable for therapeutic drug monitoring of LIN and CEF in clinical settings.

Nanoplastic Sample Cleanup by Micro-Electromembrane Extraction across Free Liquid Membranes.

Sample preparation techniques enabling the separation and cleanup of nanoplastics removing other components present in complex sample matrices are scarce. Herein, micro-electromembrane extraction (μ-EME) has been explored for this purpose based on the extraction of nanoplastic particles across a free liquid membrane (FLM). The extraction unit is based on a perfluoroalkoxy tube sequentially filled with the acceptor solution (20 μL 5 mM phosphate buffer, pH 10.7), FLM (10 μL 1-pentanol), and donor solution (20 μL sample/standard solution). Sulfonated polystyrene beads (200 nm particle size) were selected as a model mimicking negatively charged nanoplastics. At 700 V, nanoplastics transferred from the donor solution into the FLM before moving across the FLM into the acceptor solution. Quantitative nanoplastic measurements after μ-EME were performed by injecting the acceptor solution into a capillary electrophoresis system with diode array detection. μ-EME allowed the rapid nanoplastic sample cleanup, requiring an extraction time of just 90 s and obtaining a nanoplastic transfer yield through the FLM of 60% with RSD values below 9%. The μ-EME technique enabled the efficient sample matrix cleanup of nanoplastics spiked in different tea matrices. Nanoplastic transfer yield through the FLM for black tea and flavored tea matrices were 56% and 47%, respectively, with complete sample matrix removal of UV-absorbing compounds.

ALTERNATIVE NON-TRADITIONAL SOURCES OF FEED PROTEIN AND AMINO ACIDS

The article presents a literature review on the risks of the global problem of fodder protein and protein amino acids in the feeding of agricultural animals and poultry. Alternative ways of solving it are due to the production and use of non-traditional feed raw materials in feed diets. A number of scientists consider atypical agricultural biotechnological products obtained from insects to be one of the alternative sources of fodder protein and amino acids and see prospects in the development of their production. The most common subjects for study in this regard are crickets, locusts, silkworm larvae, flies, worms, etc. Their protein value, amino acid, fatty acid and mineral composition, the content of vitamins, and other biologically active substances are studied. The development of this direction is considered one of the ways to solve a number of urgent environmental and fodder problems on a biological basis. Рurpose of the research was to study the protein value and complete amino acid composition of flour from insects, namely flour from the larvae of the BSF fly, crickets and snails, and the methods of its determining: crude protein by the Kjeldahl method, digestible protein with the help of 0,2% pepsin, and the digestibility coefficient, and the principles of conducting researches, as well as the characteristics of methods for determining the content of replaceable and essential amino acids, including sulfur-containing, using the Kapel-105M capillary electrophoresis system. As a result of the research, it was found that cricket flour is the least valuable in terms of protein value (digestible protein and digestibility coefficient), and it is also poor in the content of nonessential and essential amino acids, compared to other studied types of insect flour. The best indicators of protein value were noted in the flour from BSF fly larvae in terms of the content of crude and digestible proteins, as well as the digestibility coefficient, which is 75.6%, which indicates its good digestibility by the bodies of animals and birds. The highest content of amino acids is contained in the flour from BSF fly larvae. Taking into account the above results of crude protein content, digestibility, and digestibility in this sample, amino acid digestibility will also be higher compared to other flour samples. In addition, flour from BSF fly larvae is rich in sulfur-containing amino acids. The content of tryptophan and histidine, compared to other types of raw materials, is the highest. The studied samples of insect flour contain a complete set of essential and nonessential amino acids, but BSF fly larvae flour and snail flour are more valuable for essential amino acids.

Capillary Electrophoresis as a Complementary Analytical Tool for the Separation and Detection of Nanoplastic Particles.

Capillary electrophoresis (CE) is presented as a technique for the separation of polystyrene nanoparticles (NPs, particle diameters ranging from 30 to 300 nm) through a bare fused silica capillary and ultraviolet detection. The proposed strategy was also assessed for other types of nanoplastics, finding that stronger alkaline conditions, with an ammonium hydroxide buffer (7.5%, pH = 11.9), enabled the separation of poly(methyl methacrylate), polypropylene, and polyethylene NP for the first time by means of CE for particle diameters below 200 nm. Particle behavior has been investigated in terms of its effective electrophoretic mobility, showing an increasing absolute value of effective electrophoretic mobility from the smaller to the larger sizes. On the other hand, the absolute value of surface charge density decreased with increasing size of NPs. It was demonstrated and quantified that the separation mechanism was a combination of linear and nonlinear electrophoretic effects. This work is the first report on the quantification of nonlinear electrophoretic effects on nanoplastic particles in a CE system.

Development of a capillary temperature control system for capillary electrophoresis instruments designed for spaceflight applications.

Capillary temperature control during capillary electrophoresis (CE) separations is key for achieving accurate and reproducible results with a broad array of potential methods. However, the difficulty of enabling typical fluid temperature control loops on portable instruments has meant that active capillary temperature control of in situ CE systems has frequently been overlooked. This work describes construction and test of a solid-state device for capillary temperature control that is suitable for inclusion with in situ instruments, including those designed for space missions. Two test articles were built, a thermal mass model (TMM) and a functional model (FM). The TMM demonstrated that temperature gradients could be limited using the proposed control scheme, and that our thermal modeling of the system can be relied on for future adaptations of physical geometries of the system. The FM demonstrated CE analytical performance while under active temperature control and that the device was compatible with the harsh thermal-vacuum environments that might be encountered during space flight.

A novel method of multiplex SNP genotyping assay through variable fragment length allele-specific polymerase chain reaction: Multiplex VFLASP-ARMS

Variable Fragment Length Allele-Specific Polymerase Chain Reaction (VFLASP) and Amplification Refractory Mutation System (ARMS) are reliable methods for detecting allelic variations resulting from single base changes within the genome. Due to their widespread application, allele variations caused by Single Nucleotide Polymorphisms (SNPs) can be readily detected using allele-specific primers. In the context of the current study, VFLASP was combined with ARMS method as a novel strategy to enhance the efficacy of both techniques. Clinically important base variations within SNP regions used in the study were detected by a fragment analysis method. To validate the accuracy of the developed VFLASP-ARMS method, specifically designed synthetic sequences were tested using a capillary electrophoresis system. Allele-specific primers exhibit differences solely at the 3′ end based on the sequence of the SNP. Additionally, to increase the specificity of the primers, a base was intentionally added for incompatibility. Therefore, allele discrimination on fragment analysis has been made possible through the 3–6 bp differences in the amplicons.With the optimization of the system, designed synthetic sequences provided reliable and reproducible results in wild-type, heterozygous, and homozygous genotypes using the VFLASP-ARMS method. Hence, our results demonstrated that VFLASP-ARMS method, offers a novel design methodology that can be included in the content of SNP genotyping assays.

Construction and Application of a Novel Universal Detection System for High Performance Capillary Electrophoresis

Construction and Application of a Novel Universal Detection System for High Performance Capillary Electrophoresis

Association of serum protein electrophoresis with clinicopathological characteristics and its prognostic relevance in chronic lymphocytic leukaemia patients.

To assess the association of serum protein electrophoresis abnormalities with clinicopathological characteristics, and its impact on overall survival in chronic lymphocytic leukaemia patients. The prospective study was conducted at Haematology and Immunology departments of the University of Health Sciences, Lahore, Pakistan, from 2019 to 2022, and comprised newly diagnosed chronic lymphocytic leukaemia patients. Lactate dehydrogenase and beta-2 microglobulin levels were measured by spectrophotometric principle, whereas serum protein electrophoresis was determined through commercially available capillary electrophoresis systems. Patients were followed up for 2 years post-diagnosis. Data was analysed using SPSS 21. Of the 50 patients, 40(80%) were males and 10(20%) were females. The overall mean age was 60±11 years. Serum protein electrophoresis was available for 40(80%) patients, and, among them, 12(30%) patients had abnormal levels, while 29(72.5%) required treatment. Overall response rate was 25(86.2%), and median two-year overall survival was 16.5 months (95% confidence interval: 10-20 months). Abnormal serum protein electrophoresis was significantly associated with Binet stage C, lower mean haemoglobin levels and higher median levels of lactate dehydrogenase and beta-2 microglobulin (p<0.05)). Regarding overall survival, the survival curves of chronic lymphocytic leukaemia patients with normal and abnormal serum protein electrophoresis status differed significantly (p=0.04). Abnormal serum protein electrophoresis could be considered a surrogate marker for advanced chronic lymphocytic leukaemia disease.

Capillary electrophoresis using triple layer modified capillary facilitating salivary ion analyses: Application to search for potential stress markers induced by cold pressure test

In this study, we introduce a novel approach for the analysis of salivary ions using capillary electrophoresis (CE) with a triple-layer coated capillary. The capillary is sequentially coated with cationic silylating reagents, poly(vinylsulfonate), and polybrene to form a custom designed surface that effectively inhibits adsorption of protein matrix on the capillary inner wall and allows for reproducible ion analysis. For the CE with capacitively coupled contactless conductivity detection, we used suitable background electrolytes (BGEs) for salivary ion analysis. Anions were separated using a mixture of 2-(N-morpholino)ethanesulfonic acid and l-arginine, and cations were separated using that with 18-crown-6. This setup enabled rapid separation, within 4 min, together with sensitive detection. We quantified nine common anions and five cations typically found in saliva samples using this CE method, both before and after a cold pressure test (CPT, a standard stress test). The CE system demonstrated consistent ion separation across 30 consecutive measurements without requiring capillary replacement. Notably, the salivary ion balance remained predominantly anion-rich, regardless of the CPT. Cold water exposure induced greater variation in the total anion concentration than in the total cation concentration. Further analysis using multiple regression analysis revealed strong relationships between nitrate and nitrite, formate and phosphate, and potassium and nitrate, before and after the CPT. Notably, potassium and nitrate ions exhibited variations in response to stress. These results provided a method for assessing salivary ion composition and insights into the potential of salivary ions as biomarkers for stress.

ВИТАМИНЫ, МИНЕРАЛЬНЫЕ И АРОМАТОБРАЗУЮЩИЕ ВЕЩЕСТВА В СТРУКТУРНЫХ ЭЛЕМЕНТАХ ЯГОДЫ ВИНОГРАДА СОРТОВ НАРМА И РКАЦИТЕЛИ

Grape berries, which contain organic substances, vitamins, amino acids, minerals, aromatic substances, have valuable taste and nutritional properties. An important source of biologically active substances are the pulp, skin and seeds of grape berries containing a significant amount of essential components. The purpose of the work is to determine the biochemical parameters: biologically active, mineral and aroma-forming substances in the structural elements of Narma and Rkatsiteli grape varieties cultivated in Dagestan. A capillary electrophoresis system was used to determine vitamins, composition and number of cations. The research was carried out on the device «Kapel 104T», RF, NPF LUMEX. The aroma-forming components in the experimental samples were identified using a gas chromatograph «Crystal 2000M» (RF). The mass concentration of antioxidants was measured on the device TSVET YAUZA 01-AA, (RF). The total amount of vitamins and vitamin-like substances in the autochthonous Narma variety was: in the pulp - 0.7123 mg/dm3 , in the skin – 3.4101 mg/dm3 and in the seeds – 3.7827 mg/dm3 . The total concentration of mineral elements in the skin of the studied grapes (Narma –33,2 mg/dm3 , Rkatsiteli – 20,8 mg/dm3 ) is higher than in the pulp and seeds. Significant total amounts of antioxidants were found in the seeds of the studied grapes: Narma – 6.71 mg/dm3 , Rkatsiteli – 8.51 mg/dm3 . High concentrations of aroma-forming substances were determined in the skin and seeds of berries of the Narma variety – 376.26 and 253.71 mg/dm3 , and in the Rkatsiteli variety the content of these compounds was 82.34 and 91.00 mg/dm3 , respectively. The research results complement the biochemical characteristics of Narma and Rkatsiteli grape varieties, which can be successfully used as raw materials in the food industry to enrich food with biologically active, mineral and aroma-forming substances.

Direct SARS-CoV-2 Detection System Utilizing Simple-to-Use Capillary Gel Electrophoresis Sample-to-Result.

We present a Direct SARS-CoV-2 Detection System that achieves sample-to-results in less than two hours in three simple steps. The Detection System includes Direct one-step Reverse Transcription PCR (RT-PCR) reagents (Qexp-MDx kit), a portable thermal cycler (Qampmini) with a preprogrammed chip and a simple-to-use Capillary Gel Electrophoresis system (Qsep Series Bio-Fragment Analyzer) with high fluorescence detection sensitivity to solve the problems associated with traditional real-time PCR (qPCR) systems which produces high false positive results. The proposed simple-to-use detection platform can provide high detection sensitivity (identify less than 20 copies) and fast results (less than 120 minutes), which would be suitable for field testing applications. Our high detection sensitivity platform provides fast and accurate results in 120 minutes without doing DNA/RNA extraction.

Определение анионов неорганических кислот в спиртных дистиллированных напитках методом капиллярного электрофореза с кондуктометрическим детектированием

Distilled alcoholic drinks are popular all over the world. Monitoring the quality and safety of such drinks requires modern instrumental methods. Chemical composition of alcoholic beverages has become focus of numerous experimental and theoretical publications. However, this area remains understudied. This research provided an experimental confirmation of the capillary electrophoresis as a prospective method for determining anions in alcoholic beverages.&#x0D; The study involved model solutions and 30 samples of distilled alcoholic beverages purchased by random sampling from a retail chain. The chemical analysis relied on a PrinCE 560 capillary electrophoresis system equipped with a conductometric detector.&#x0D; The study revealed the working parameters for electrophoretic analysis that provided a selective qualitative and quantitative test of five target analytes in 9 min. The optimal composition of the buffer solution and the optimal electrolyte ratios were 30 mmol/dm3 L-Histidine and 30 mmol/dm3 2-(N-Morpholino) ethanesulfonic acid Monohydrate. The correlation between the peak area and the mass concentration was at 0.1–10 mg/dm3 for the target analytes. The approach proved effective in determining chloride, nitrate, sulfate, fluoride, and phosphate ions in whiskey, rum, tequila, moonshine, grain, and rum distillates. The study also included a comparative analysis of the qualitative and quantitative anion profiles in whiskey samples from different countries. All the samples contained 0.22–52.74 mg/dm3 chlorides, 0.60–0.06 mg/dm3 nitrates, 0.25–17.59 mg/dm3 sulfates, and 0.75–12.70 mg/dm3 phosphates.&#x0D; Research prospects include a metrologically certified method to identify the anion composition of organic and inorganic acids in distilled alcoholic beverages.

Study of Sorption of Chlortetracycline Hydrochloride and Its Subsequent Determination by Capillary Zone Electrophoresis

The work deals with the development of an approach to the determination of chlortetracycline, which combines the preconcentration of the analyte with its subsequent determination by capillary zone electrophoresis. The conditions that ensure the lowest value of the limit of determination for chlortetracycline in aqueous solutions using a Kapel-105M capillary electrophoresis system (Lumex, Russia) are determined, i.e., temperature, time and pressure of sample injection, background electrolyte composition, and detection wavelength. It is shown that the stability of a chlortetracycline solution is maximum at a storage temperature of 0.5°С in the absence of buffer systems or in using a dilute ammonium acetate buffer solution. It is found that the recovery of chlortetracycline by strongly acidic cation exchangers KU-1, KU-2 is higher compared to that by KB-4 and KB-4P2, bearing weakly acidic functional groups. The conditions under which the recovery of the analyte by KU-1 from a phosphate buffer solution is about 90% are determined.

A Mission Simulating the Search for Life on Mars with Automated Drilling, Sample Handling, and Life Detection Instruments Performed in the Hyperarid Core of the Atacama Desert, Chile.

We report on a field demonstration of a rover-based drilling mission to search for biomolecular evidence of life in the arid core of the Atacama Desert, Chile. The KREX2 rover carried the Honeybee Robotics 1 m depth The Regolith and Ice Drill for Exploration of New Terrains (TRIDENT) drill and a robotic arm with scoop that delivered subsurface fines to three flight prototype instruments: (1) The Signs of Life Detector (SOLID), a protein and biomolecule analyzer based on fluorescence sandwich microarray immunoassay; (2) the Planetary In Situ Capillary Electrophoresis System (PISCES), an amino acid analyzer based on subcritical water extraction coupled to microchip electrophoresis analysis; and (3) a Wet Chemistry Laboratory cell to measure soluble ions using ion selective electrodes and chronopotentiometry. A California-based science team selected and directed drilling and sampling of three sites separated by hundreds of meters that included a light-toned basin area showing evidence of aqueous activity surrounded by a rocky desert pavement. Biosignatures were detected in basin samples collected at depths ranging from 20 to 80 cm but were not detected in the surrounding area. Subsurface stratigraphy of the units drilled was interpreted from drill sensor data as fine-scale layers of sand/clay sediments interspersed with layers of harder material in the basins and a uniform subsurface composed of course-to-fine sand in the surroundings. The mission timeline and number of commands sent to accomplish each activity were tracked. The deepest sample collected (80 cm) required 55 commands, including drilling and delivery to three instruments. Elapsed time required for drilling and sample handling was less than 3 hours to collect sample from 72 cm depth, including time devoted to recovery from a jammed drill. The experiment demonstrated drilling, sample transfer technologies, and instruments that accomplished successful detection of biomolecular evidence of life in one of the most biologically sparse environments on Earth.