Fast Sample Preparation Method Research Articles

Pouring and Curing for Sample Preparation Technology for the Analysis of the Silicon-Aluminum Ratio of Molecular Sieves by Energy Dispersive X-Ray Fluorescence (EDXRF)

The silicon-aluminum ratio of the molecular sieves is a crucial control index for the quality of synthetic molecular sieves. Here a fast, simple and reliable sample preparation method, referred to as pouring and curing method, is described for determining the silicon-aluminum ratio of high silicon molecular sieves by energy dispersive x-ray fluorescence (EDXRF). Resin is used as the carrier with the addition of a curing agent, so that the sample powder is embedded in the resin matrix. By measuring sixteen random positions of the same cured sample, the homogeneity of the sample was evaluated to ensure the stability of the results. A double logarithmic calibration curve of the analysis line ratio and the corresponding concentration ratio of silicon and aluminum was established according to the binary ratio method. The results by EDXRF and inductively coupled plasma-optical emission spectrometer (ICP-OES) were compared with a relative standard error from 2.934 to 6.777%. The good precision shows that the pouring and curing method is a suitable for measuring the silicon-aluminum ratio of molecular sieves.

A simple, low cost and fast sample preparation method for fluorine determination by ISE in leguminous seeds and oilseeds.

This work presents the first report of the application of microwave-induced combustion in disposable vessels (MIC-DV) as a simple and fast sample preparation step for fluoride determination by ion-selective electrode (ISE) in leguminous seeds and oilseeds samples. Several experimental conditions of MIC-DV were evaluated, such as sample mass, absorbing solution, volume of combustion igniter, purging time with oxygen, and the use of successive combustion cycles. The accuracy of MIC-DV/ISE method was evaluated by comparing the results obtained by microwave-induced combustion and determination by ion chromatography, with agreements ranged from 94 to 106%. The method allowed to achieve relatively low limits of quantification (8.3 to 16µgg-1) comparing to AOAC method (40µgg-1), besides the use of small amounts of reagents, less handling of digests, making the method greener and with portable features comparing to other methods.

Determination of Cl and S in crude oil by ICP-OES after sample digestion by microwave-induced combustion in disposable vessels

A simple, fast and promising sample preparation method based on microwave-induced combustion in disposable vessels (MIC-DV) was developed for Cl and S determination in crude oil by inductively coupled plasma optical emission spectrometry (ICP-OES). The MIC-DV consists of a new approach of conventional microwave-induced combustion (MIC). For the combustion, crude oil was pipetted on a disk of filter paper and placed on a quartz holder, followed by the addition of igniter solution (40 μL of 10 mol L−1 NH4NO3). The quartz holder was inserted into a commercial 50 mL disposable polypropylene vessel containing the absorbing solution, which was then inserted in an aluminium rotor. The combustion occurs under atmospheric pressure in a domestic microwave oven not compromising the operator's safety. The following parameters of combustion were evaluated: type, concentration and volume of absorbing solution, sample mass and the possibility of performing consecutive combustion cycles. Using MIC-DV, up to 10 mg of crude oil were efficiently digested, using 2.5 mL of ultrapure H2O as absorbing solution. Moreover, up to 5 consecutive combustion cycles were possible without analyte losses, reaching a total sample mass of 50 mg. The MIC-DV method was validated according to Eurachem Guide recommendations. Results obtained for Cl and S by MIC-DV were in agreement with those obtained using conventional MIC, as well as those obtained for S in a certified reference material of crude oil (NIST 2721). Analyte spike recovery experiments were performed and recoveries at three concentration levels ranged from 99 to 101% for Cl and from 95 to 97% for S, indicating a good accuracy. The limit of quantification achieved by ICP-OES after MIC-DV were 73 and 50 μg g−1 for Cl and S respectively, applying 5 consecutive combustion cycles.

Enterokokların MALDI-TOF MS’de Slanetz ve Bartley ve Kanlı Agar Besiyeri ile Karşılaştırılarak Tanımlanması

Introduction: Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been used frequently in the last decade as a fast and reliable method for the identification of microorganisms. The fact that only one gram-negative selective medium is recommended in this method causes problems in the diagnosis. There is no information in the scientific literature that Slanetz and Bartley (SB) agar used in the study can be used in MALDI-TOF MS to identify bacteria. Materials and Methods: In this study, it was aimed to compare the identification performance of enterococci isolated from drinking-use and lake waters in Van and its surroundings with blood agar by using MALDI-TOF MS method and to develop a simple and fast sample preparation method that increases this performance. For this purpose, 60 mains and 30 lake water samples were examined for six months. Results: The samples were studied by the membrane filtration method. The isolated enterococci were identified by MALDI-TOF MS method with the isolates taken directly from both blood agar and SB medium, which is a selective medium. The same results were obtained in the species determination in both media. According to these results, 35% of the mains water isolates were Enterococcus casseliflavus, 30% Enterococcus faecalis, 26.7% Enterococcus faecium, 6.6% Enterococcus hirae, 1.7% Enterococcus columbae, and 20% of lake water isolates E. casseliflavus, 40% E. faecalis, 36.7% E. faecium, 3.3% E. hirae, E. casseliflavus in mains water and E. faecalis in lake water are the most frequently isolated enterococci species. Conclusion: Determining that it can also be obtained from selective media such as SB agar, for which there is no data on its suitability for mass spectrometric identification, will contribute to the more effective and rapid use of MALDI-TOF MS in microbiology laboratories. In addition, it has been concluded that all the waters examined are exposed to a significant level of microbial contamination and pose a potential danger to public health. It has been revealed that the consumption of these waters may pose a potential health risk for immunocompromised patients and the elderly, as well as children.

Magnetic solid phase extraction of Sunitinib malate in urine samples assisted with mixed hemimicelle and spectrophotometric detection

The mixed hemimicelle-based solid phase extraction method using the coated sodium dodecyl sulfate by magnetic iron oxide nanoparticles as adsorbent was developed for extraction and determination of Sunitinib malate in real samples prior to determination by UV–Visible spectrophotometry. For the characterization of synthesized nanoparticles, Fourier transform infrared spectroscopy, and scanning electron microscopy was used. The influences of different factors affecting the extraction efficiency of Sunitinib malate, including the pH, the adsorbent amount, the volume and eluent type, the amount of the surfactant, the ionic strength, extraction, and desorption time, were investigated. At the optimized conditions, a good linearity with correlation coefficients of 0.998 and 0.999 was obtained over the concentration ranges of 1–22 and 1–19 µg/mL for water and urine samples, in order. The good recoveries of 97% and 99% and also, the limits of detection equal with 0.9, and 0.8 µg/mL for water and urine samples were enhanced, respectively. These results demonstrate that mixed hemimicelle solid phase extraction is a fast, efficient, economical and selective sample preparation method for the extraction and determination of Sunitinib malate in different water and urine sample solutions.

Riboflavin as a green sorbent in dispersive micro-solid-phase extraction of several pesticides from fruit juices combined with dispersive liquid-liquid microextraction.

A vortex-assisted dispersive micro-solid-phase extraction procedure using a new and green sorbent was developed as a simple, fast, and efficient sample preparation method for the extracting five pesticides in several fruit juice samples. In this study, for the first time, riboflavin was used as an efficient sorbent. A few milligrams of riboflavin was directly added into the aqueous solution containing the analytes to adsorb them. After adsorption the analytes, they were desorbed and more concentrated by a dispersive liquid-liquid microextraction procedure. The influence of several effective parameters such as amount of riboflavin, pH, vortex time, eluent nature and volume, and extraction solvent type and volume on the extraction efficiency was investigated. In optimal conditions, linear ranges of the calibration curves were broad. The limits of detection and quantification were attained in the ranges of 0.56-1.5 and 1.9-0.52ng mL-1 , respectively. The proposed method demonstrated to be suitable for concurrent extraction of the studied pesticides in various fruit juice samples with high enrichment factors (320-360) and precision (relative standard deviation ≤7.8% for intra- [n=6] and interday [n=4] precisions at a concentration of 25ng mL-1 of each pesticide).

Fast determination of phthalates in mussel samples by micro-matrix solid-phase dispersion (micro-MSPD) coupled with GC\u2013MS/MS

A fast, effective and low cost sample preparation method based on miniaturized matrix solid-phase dispersion (micro-MSPD) combined with gas chromatography coupled to tandem triple-quadrupole-mass spectrometry (GC–MS/MS) has been developed for the determination of six phthalate diesters (DMP, DEP, DBP, BzBP, DEHP and DnOP) in mussel samples. The six target compounds have been included in the list of priority pollutants by United States Environmental Protection Agency. The extraction step was optimized on real spiked mussel coming from Galician Rías by means of a factorial design. The final procedure involved the use of 0.45 g of sample, 0.5 g of dispersant agent (Florisil) and 3 mL of organic solvent (ethyl acetate). The optimized method was validated giving satisfactory analytical performance, low detection limits (0.09 to 6.73 ng g−1 dw) and high recoveries (93 and 114%). The validated method was applied to four real mussel samples coming from Galician Rías.

An in vitro assessment for human skin exposure to parabens using magnetic solid phase extraction coupled with HPLC

Skin contact was a significant source of human exposure to parabens during the use of personal care products. In this study, a novel and simple in vitro evaluation method for human skin exposure to parabens was established for the first time. Firstly, magnetic porous carbon (MPC) derived from discarded cigarette butts was prepared as an adsorbent of magnetic solid-phase extraction (MSPE), which provided a fast and efficient sample preparation method with satisfactory extraction performance for parabens in cosmetics and was easy to couple with high performance liquid chromatography. Secondly, the extraction conditions were optimized including the etching ratio of KOH, amount of MPC, extraction time, pH, salt concentration, desorption solvent volume and desorption time. Under the optimized conditions, the limits of detection were between 0.25 and 0.34 ng mL−1 and the spiked recoveries were in the range of 85.8–112.6%. Thirdly, the developed method was successfully employed to determine five typical parabens in real unspiked cosmetic samples, and two parabens were detected at a relatively high level. Then, the developed method was applied to in vitro assays. The absorbable dose of parabens in cream was investigated and in vitro experiments were further designed with agarose-simulated skin to demonstrate the penetration ability of parabens. In conclusion, these results indicated that parabens did have the risk of entering the body through the skin and the exposure was preferably no more than 3 h with skin contact.

Simple and efficient method for the determination of fipronil and two main metabolites in eggs by capillary liquid chromatography

Capillary liquid chromatography (CLC) with UV-diode array detection has been proposed for the first time to determine fipronil and two metabolites, fipronil-sulfide and fipronil-sulfone in hen egg samples. Under optimum conditions, analytes eluted in less than 12 min. Despite the complexity of egg samples, a simple and fast sample preparation method based on salting-out assisted liquid–liquid extraction (SALLE) was developed using acetonitrile as extraction solvent and ammonium sulfate as salting out reagent. To obtain satisfactory extraction efficiencies for the target compounds, several parameters affecting the procedure were optimized, including the nature and amount of the extraction solvent and the type and amount of salting-out reagent, among others. Validation parameters of the proposed SALLE-CLC-UV method yielded satisfactory results with repeatability and intermediate precision, expressed as relative standard deviation (RSD), below 9% and 11%, respectively and recoveries above 80%. Good linearity was obtained (R2 > 0.990) with limits of detection (LOD) below 5 μg·kg−1. The advantages of a miniaturized technique such as CLC in terms of reduced sample and solvent consumption, combined with simplicity of the SALLE procedure, make this method an attractive green alternative to traditional LC for the monitoring of these residues in egg samples.

Development of an Analytical Method for Rapid Metal Determination in Stingless Bee Honey

Stingless bee honey is a product used for different purposes due to its composition, in which the presence of metallic species is highlighted. Depending on their amount, they may have either a nourishing or a toxic effect. Flame atomic absorption spectrometry (FAAS) is a commonly used technique for quantifying metals in samples such as honey. However, because of the complexity of the matrix, the sample must go through a preparation step for the analytes to be available for quantification. In the present work, a fast and efficient sample preparation method for the quantification of metallic ions in stingless bee honey was optimized, from the direct analysis of slurries using FAAS. The samples were suspended using honey (1.0 g and 2.5 g), nitric acid (1.4 mol L-1 and 0.2 mol L-1), hydrogen peroxide (1% and 3%) and ultrasonic agitation (5 and 10 minutes). Then, the proposed analytical method was validated by evaluating parameters such as linearity, limits of detection and quantification, precision and accuracy, all with adequate values ​​compared to those established in the literature. DOI: http://dx.doi.org/10.17807/orbital.v13i2.1449

A simple and fast sample preparation method based on ionic liquid treatment for determination of Cd and Pb in dried solid agricultural products by graphite furnace atomic absorption spectrometry

The Cd and Pb are two typical heavy metal contaminants of agricultural products which have posed great threats to human health. The precise determination of Cd and Pb in agricultural products is extremely important for human health. In this paper, a simple and fast sample preparation method based on ionic liquid treatment was proposed to determine Cd and Pb in dried solid agricultural products by graphite furnace atomic absorption spectrometry (GFAAS). The samples were prepared by dissolving the tested agricultural products into the ionic liquid 1-butyl-3-methylimidazolium chloride. The temperature program and matrix modifiers for GFFAS analysis of these samples were optimized. The reliability of sample preparation was verified by comparing the between- and within-batch precision, which showed no significant differences at 95% confidence level. Detection limits were 0.019 μg L−1 Cd and 0.042 μg L−1 Pb for these samples. Results for determining Cd and Pb in these samples were in good agreement with those obtained from the conventional wet digested samples. Both the certified reference materials validation experiments and the spiked and recovery tests indicated this sample preparation for determining Cd and Pb had satisfactory accuracy and could be an alternative to traditional sample preparation.

SCASP: A Simple and Robust SDS-Aided Sample Preparation Method for Proteomic Research

AbstractSDS is widely used in sample preparation for proteomic research. However, SDS is incompatible with LC and electrospray ionization. SDS depletion is therefore required ahead of LC–MS analysis. Most of current SDS removal strategies are time consuming, laborious, and have low reproducibility. Here, we describe a method, SDS–cyclodextrin (CD)-assisted sample preparation, by which CD can bind to SDS and form CD–SDS complexes in solutions, allowing for direct tryptic digestion. We demonstrate that SDS–CD-assisted sample preparation is a simple, fast, and robust SDS-based sample preparation method for proteomics application.

Reversed-phase dispersive liquid–liquid microextraction for elemental analysis of gasoline by inductively coupled plasma optical emission spectrometry

A green and fast sample preparation method based on reversed-phase dispersive liquid–liquid microextraction was developed for the separation and preconcentration of several elements in gasoline samples before ICP-OES determination.

Miniaturized Salting-Out Assisted Liquid-Liquid Extraction Combined with Disposable Pipette Extraction for Fast Sample Preparation of Neonicotinoid Pesticides in Bee Pollen.

As the main source of nutrients for the important pollinator honeybee, bee pollen is crucial for the health of the honeybee and the agro-ecosystem. In the present study, a new sample preparation procedure has been developed for the determination of neonicotinoid pesticides in bee pollen. The neonicotinoid pesticides were extracted using miniaturized salting-out assisted liquid-liquid extraction (mini-SALLE), followed by disposable pipette extraction (DPX) for the clean-up of analytes. Effects of DPX parameters on the clean-up performance were systematically investigated, including sorbent types (PSA, C18, and silica gel), mass of sorbent, loading modes, and elution conditions. In addition, the clean-up effect of classical dispersive solid-phase extraction (d-SPE) was compared with that of the DPX method. Results indicated that PSA-based DPX showed excellent clean-up ability for the high performance liquid chromatography (HPLC) analysis of neonicotinoid pesticides in bee pollen. The proposed DPX method was fully validated and demonstrated to provide the advantage of simple and rapid clean-up with low consumption of solvent. This is the first report of DPX method applied in bee pollen matrix, and would be valuable for the development of a fast sample preparation method for this challenging and important matrix.

A Simple, Fast, and Green Oil Sample Preparation Method for Determination of Cannabidioloic Acid and Cannabidiol by HPLC-DAD

Currently, the medical use of food supplements containing Cannabis sativa has attracted the interest of consumers, as well as the medical and scientific community. With the increasing consumption of these products, there is also a risk of their abuse or discrepancy between the actual and declared contents of active substances by the manufacturer in these products. Thus, the development and elaboration of analytical procedures for determination of appropriate phytocannabinoids seems to be important. This work focuses on the development of a simple, fast and environmentally friendly liquid-liquid extraction method combined with fat freezing from an oil sample to isolate two phytocannabinoids: cannabidiol (CBD) and cannabidiolic acid (CBDA). The extraction method was optimized considering efficacy and repeatability of extraction, as well as minimalizing use of organic reagents and sample amount. Under the optimized conditions, extraction recovery for CBD was 97.3–109% and for CBDA was 69.1–69.5% with precision (RSD, %) 5.0–8.4 and 7.1–10.6, respectively. The evaluated main analytical parameters of the developed high pressure liquid chromatography with diode array detector (HPLC-DAD) method for both studied cannabinoids are satisfactory. The usability of the developed method was checked by analysis of real samples of a food supplement–hemp oil enriched with CBD.

Fast, Robust, and Sensitive Identification of Residual Host Cell Proteins in Recombinant Monoclonal Antibodies Using Sodium Deoxycholate Assisted Digestion.

Residual host cell proteins (HCPs) present in biotherapeutics can pose potential safety risks for patients or affect product stability, thus prompting a critical need to monitor HCPs in drug substance or product to ensure product safety and quality. Current approaches for robust HCP identification at or above 10 ppm levels require either concatenated peptide fractionation or enrichment via antibody depletion, which challenges the direct quantitation of HCPs. This paper describes a simple, fast sample preparation method without the need for sample fractionation or enrichment; instead, we utilize trypsin-friendly sodium deoxycholate (SDC) as an advantageous denaturant that can be effectively removed following acidification at the end of sample digestion. This new approach enables the end-to-end one-dimensional liquid chromatography-tandem mass spectrometry (1D LC-MS/MS) workflow (i.e., from sample preparation to HCP identification) to be completed in 7-8 h while demonstrating the ability to consistently identify HCPs across a broad molecular weight range at 10 ppm or above.

Improved QuEChERS for Analysis of Polybrominated Diphenyl Ethers and Novel Brominated Flame Retardants in Capsicum Cultivars Using Gas Chromatography

One of the main challenges for analytical laboratories and food safety authorities is the control of food contaminants hazardous to human health. For the first time, a simple, fast, and cost-effective sample preparation method is proposed as an extraction technique to determine 12 brominated flame retardants (BFRs) (seven polybrominated diphenyl ether (PBDE) congeners and five novel BFRs) in Capsicum cultivars. Different QuEChERS and dispersive solid-phase extract (d-SPE) sorbent compositions were evaluated in terms of recovery and matrix effects. The best results were obtained with citrate-buffered version QuEChERS and a cleanup step, with 150 mg of MgSO4, 50 mg of primary secondary amine (PSA), 50 mg of C18, and 5 mg of carbon. The limit of detection (LOD) was between 1.4 and 9.3 μg/kg and R2 > 0.99. Recoveries and matrix effects were between 66 and 104% and 0.58 and 2.18, respectively. The relative standard deviations from repeatability and reproducibility studies and estimation of measurement uncertainty were lower than 20%. Gas chromatography coupled with a mass spectrometer was used to confirm the presence of BFRs in the samples. Novel BFRs were detected lower than the LOD.

A Simple and Rapid LC-MS/MS Method for Quantification of Total Daidzein, Genistein, and Equol in Human Urine.

Isoflavones and isoflavandiols have shown many health benefits, such as reducing cardiovascular disease, cancer, age-related disease, and osteoporosis. However, to investigate the relationships between consumption of isoflavones and their health benefits, it is important to be able to accurately quantify exposure in the large numbers of samples typically produced in association studies (i.e., several thousands). Current methods rely on solid-phase extraction protocols for sample cleanup, resulting in protracted extraction and analysis times. Here, we describe a fast and easy sample preparation method of human urine samples for subsequent quantification of daidzein, genistein (isoflavones), and equol (isoflavandiol) using LC-MS/MS. Sample preparation involves only the addition of dimethylformamide (DMF) and formic acid (FA) after enzymatic hydrolysis of their metabolites by a β-glucuronidase and sulfatase mixture. The method was validated by precision, linearity, accuracy, recoveries, limit of detection (LOD), and limit of quantification (LOQ). Linear calibration curves have been shown by daidzein, genistein, and equol. The correlation coefficients values are r2 > 0.99 for daidzein, genistein, and equol. LOD for daidzein and genistein was 1 ng/ml and equol was 2 ng/ml. Recoveries were >90%, and the relative standard deviation for intraday (<10%) and interday (≤20% over 10 days) was good. This method is suitable for quantification of isoflavones and the microbial metabolite equol in human urine and is particularly useful where large numbers of samples require analysis.

Lookup Table-Based Fast Reliability-Aware Sample Preparation Using Digital Microfluidic Biochips

Reliability of the prepared fluidic samples is a major concern for automated sample preparation using microfluidic biochips, where induced errors in the resultant concentration values severely affect the assay outcome. However, the existing design automation techniques have not thoroughly considered the reliability model to reduce the induced concentration errors during sample preparation. This article proposes a fast reliability-aware sample preparation (RASP) method for determining the optimized sequence of mixing steps (mixing process) with the enhanced reliability. In RASP, a probabilistic concentration prediction model is proposed for analyzing the reliability of a given mixing process. Based on this probabilistic model, a lookup table construction algorithm along with the table query method is proposed to obtain the optimized mixing process. The simulation results show that for any user-specified target concentration, RASP can effectively determine the optimized mixing process, which generates the droplets with target concentration within the error tolerance of 0.1%. Compared with the state-of-the-art sample preparation algorithm, RASP improves the reliability-related accuracy by 91.4% on average via 2048 testcases.

Air-assisted liquid–liquid microextraction combined with flame atomic absorption spectrometry for determination of trace Pb in biological and aqueous samples

ABSTRACT A fast, inexpensive, environmental-friendly and efficient sample preparation method for determination of trace amounts of Pb2+ ions in aqueous samples and humane urine is presented. Lead was extracted using the air-assisted liquid–liquid microextraction (AALLME) technique and determined by flame atomic absorption spectrometry (FAAS). O, O-diethyl dithiophosphoric acid was used as a chelating agent to form a hydrophobic complex. Several factors influencing the microextraction efficiency and the complex formation such as extraction solvent type and its volume, pH, concentration of the chelating agent and extraction time were evaluated. Under optimum conditions, the calibration graph was linear in the concentration range of 30–350 μg L−1 with a detection limit of 8.5 μg L−1. The relative standard deviation for six replicated measurements of 140 μg L−1 of Pb2+ was 4.07%. Obtained enrichment factor was 25. Through combination of AALLME with FAAS, the analytical performance of FAAS for the detection of lead greatly improved. The accuracy of the developed method was evaluated by the analysis of the certified reference material and addition recovery test. The presented method was able to analyse lead in different real samples including human urine, wastewater and water samples with satisfactory recovery ranged from 95% to 108%.