scholarly journals Estimating Diphenylamine in Gunshot Residues from a New Tool for Identifying both Inorganic and Organic Residues in the Same Sample

Separations ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 16 ◽  
Author(s):  
Ana Argente-García ◽  
Lusine Hakobyan ◽  
Carmen Guillem ◽  
Pilar Campíns-Falcó
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
High Sensitivity ◽  
Capillary Liquid Chromatography ◽  
Organic Residues ◽  
Cotton Swab ◽  
Gunshot Residues ◽  
Relative Standard ◽  
On Line ◽  
Inorganic And Organic

A method involving the collection and determination of organic and inorganic gunshot residues on hands using on-line in-tube solid-phase microextraction (IT-SPME) coupled to miniaturized capillary liquid chromatography with diode array detection (CapLC-DAD) and scanning electron microscopy coupled to energy dispersion X-ray (SEM-EDX), respectively, for quantifying both residues was developed. The best extraction efficiency for diphenylamine (DPA) as the main target among organic residues was achieved by using a dry cotton swab followed by vortex-assisted extraction with water, which permits preservation of inorganic residues. Factors such as the nature and length of the IT-SPME extractive phase and volume of the sample processed were investigated and optimized to achieve high sensitivity: 90 cm of TRB-35 (35% diphenyl, 65% polydimethylsiloxane) capillary column and 1.8 mL of the processed sample were selected for the IT-SPME. Satisfactory limit of detection of the method for analysis of DPA deposited on shooters’ hands (0.3 ng) and precision (intra-day relative standard deviation, 9%) were obtained. The utility of the described approach was tested by analyzing several samples of shooters’ hands. Diphenylamine was found in 81% of the samples analyzed. Inorganic gunshot residues analyzed by SEM-EDX were also studied in cotton swab and lift tape kit samplers. Optical microscopy was used to see the inorganic gunshot residues in the cotton swab samplers. The lift tape kits provided lesser sensitivity for DPA than dry cotton swabs—around fourteen times. The possibility of environmental and occupational sources could be eliminated when DPA was found together with inorganic residues. Then, the presence of inorganic and organic residues in a given sample could be used as evidence in judicial proceedings in the forensic field.

Calcium/Copper alginate framework doped with CuO nano-particles as a novel adsorbent for micro-extraction of benzodiazepines from human serum

2020 ◽  
Vol 16 ◽  
Author(s):  
Nadereh Rahbar ◽  
Fatemeh Ahmadi ◽  
Zahra Ramezani ◽  
Masoumeh Nourani
Keyword(s):  
Human Serum ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Nano Particles ◽  
Limit Of Quantification ◽  
Analytical Methodology ◽  
Fiber Fabrication ◽  
Relative Standard ◽  
Green Procedure

Background: Sample preparation is one of the most challenging phases in pharmaceutical analysis, especially in biological matrices, affecting the whole analytical methodology. Objective: In this study, a new Ca(II)/Cu(II)/alginate/CuO nanoparticles hydrogel fiber (CCACHF) was synthesized through a simple, green procedure and applied for fiber micro solid phase extraction (FMSPE) of diazepam (DIZ) and oxazepam (OXZ) as model drugs prior to high-performance liquid chromatography-UV detection (HPLC-UV). Methods: Composition and morphology of the prepared fiber were characterized and the effect of main parameters on the fiber fabrication and extraction efficiency have been studied and optimized. Results: In optimal conditions, calibration curves were linear ranging between 0.1–500 µg L−1 with regression coefficients of 0.9938 and 0.9968. Limit of detection (LOD) (S/N=3) and limit of quantification (LOQ) (S/N=10) of the technique for DIZ and OXZ were 0.03 to 0.1 µg L−1. Within-day and between-day relative standard deviations (RSDs) for DIZ and OXZ were 6.0–12.5% and 3.3–9.4%, respectively. Conclusion: The fabricated adsorbent has been substantially employed to extraction of selected benzo-diazepines (BZDs) from human serum real specimens and the obtained recoveries were also satisfactory (82.1-109.7%).

Development of a solid-phase extraction – spectrofluorimetric method for trace glutathione determination

2011 ◽  
Vol 89 (4) ◽  
pp. 517-523 ◽  
Author(s):  
Ke-Jing Huang ◽  
Cong-Hui Han ◽  
Ying-Ying Wu ◽  
Chao-Qun Han ◽  
De-Jun Niu ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Calibration Graph ◽  
Extraction Column ◽  
Phase Extraction ◽  
Selective Reaction ◽  
Spectrofluorimetric Method ◽  
Relative Standard

A simple and efficient solid-phase extraction – spectrofluorimetric method has been developed to determine glutathione (GSH). Fluorescent probe N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl)iodoacetamide (BODIPY Fl-C1-IA) was used as the derivatization reagent. The procedure was based on a BODIPY Fl-C1-IA selective reaction with GSH to form the highly fluorescent product BODIPY Fl-C1-IA–GSH, using a solid-phase extraction column and spectrofluorimetric determination. The variables affecting analytical performance were studied and optimized. The calibration graph using the preconcentration system for GSH was linear over the range of 1–200 nmol/L with a limit of detection of 0.05 nmol/L (signal-to-noise ratio = 3). The relative standard deviation for six replicate determinations of GSH at the 100 nmol/L concentration level was 3.9%. The method was applied to water samples and average recoveries between 87.5% and 111.5% were obtained for spiked samples.

scholarly journals Determination of 77 Multiclass Pesticides and Their Metabolitesin Capsicum and Tomato Using GC-MS/MS and LC-MS/MS

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Graphitized Carbon Black ◽  
Limit Of Quantification ◽  
Gas And Liquid Chromatography ◽  
Relative Standard ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Primary Secondary Amine

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.

Flow-Through Fourier Transform Infrared Sensor for Total Hydrocarbons Determination in Water

2009 ◽  
Vol 63 (9) ◽  
pp. 1015-1021 ◽  
Author(s):  
David Pérez-Palacios ◽  
Sergio Armenta ◽  
Bernhard Lendl
Keyword(s):  
Fourier Transform ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Chlorinated Solvents ◽  
Analytical Signal ◽  
Fourier Transform Infrared ◽  
Minimal Sample ◽  
Relative Standard ◽  
Ft Ir ◽  
Flow Through

A new flow-through Fourier transform infrared (FT-IR) sensor for oil in water analysis based on solid-phase spectroscopy on octadecyl (C18) silica particles has been developed. The C18 non-polar sorbent is placed inside the sensor and is able to retain hydrocarbons from water samples. The system does not require the use of chlorinated solvents, reducing the environmental impact, and the minimal sample handling stages serve to ensure sample integrity whilst reducing exposure of the analyst to any toxic hydrocarbons present within the samples. Fourier transform infrared (FT-IR) spectra were recorded by co-adding 32 scans at a resolution of 4 cm−1 and the band located at 1462 cm−1 due to the CH2 bending was integrated from 1475 to 1450 cm−1 using a baseline correction established between 1485 and 1440 cm−1 using the areas as analytical signal. The technique, which provides a limit of detection (LOD) of 22 mg L−1 and a precision expressed as relative standard deviation (RSD) lower than 5%, is considerably rapid and allows for a high level of automation.

scholarly journals The Usefulness of Saliva in Therapeutic Drug Monitoring of Caffeine in Preterm Infants.

2021 ◽  
Author(s):  
Ana García-Robles ◽  
Álvaro Solaz-García ◽  
Jorge Verdú-Andrés ◽  
José Luis Poveda-Andrés ◽  
Antonio José Cañada-Martínez ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Gestational Age ◽  
Solid Phase ◽  
Newborn Infants ◽  
Capillary Liquid Chromatography ◽  
Therapeutic Drug ◽  
Paired Samples ◽  
Postmenstrual Age ◽  
On Line ◽  
Array Detection

Abstract Aim To verify if the concentrations of caffeine in saliva are comparable to the serum concentrations in preterm infants treated with caffeine for apnoea of prematurity. Methods Prospective observational study. Eligible patients were newborn infants < 37 weeks of gestational age treated with oral or intravenous caffeine for apnoea of prematurity. Two paired samples of saliva-blood were collected per patient. Tube solid phase microextraction coupled on-line to capillary liquid chromatography with diode array detection were used for analysis. Results A total of 47 newborns with a median gestational age 28 [26–30] weeks and mean of 1.11 ± 0.4 kg of birth weight. Median postmenstrual age, when samples were collected, was 31 [29–33] weeks. Serum caffeine median levels of 19.30 µg/mL [1.9–53.90]and salivary caffeine median levels of 16.36 µg/mL [2.20–56.90] were obtained. There was a strong positive Pearson’s correlation between the two variables r = 0.83 (p < 0.001). Conclusion The measurement of caffeine salivary concentrations after intravenous or oral administration offers an alternative to serum caffeine monitoring in apnoea of prematurity.

scholarly journals Greener Monolithic Solid Phase Extraction Biosorbent Based on Calcium Cross-Linked Starch Cryogel Composite Graphene Oxide Nanoparticles for Benzo(a)pyrene Analysis

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6163
Author(s):  
Aree Choodum ◽  
Nareumon Lamthornkit ◽  
Chanita Boonkanon ◽  
Tarawee Taweekarn ◽  
Kharittha Phatthanawiwat ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Solid Phase Extraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
High Sensitivity ◽  
Rice Flour ◽  
Oxide Nanoparticles ◽  
Phase Extraction ◽  
Limit Of Quantification ◽  
Significant Difference

Benzo(a)pyrene (BaP) has been recognized as a marker for the detection of carcinogenic polycyclic aromatic hydrocarbons. In this work, a novel monolithic solid-phase extraction (SPE) sorbent based on graphene oxide nanoparticles (GO) in starch-based cryogel composite (GO-Cry) was successfully prepared for BaP analysis. Rice flour and tapioca starch (gel precursors) were gelatinized in limewater (cross-linker) under alkaline conditions before addition of GO (filler) that can increase the ability to extract BaP up to 2.6-fold. BaP analysis had a linear range of 10 to 1000 µgL−1 with good linearity (R2 = 0.9971) and high sensitivity (4.1 ± 0.1 a.u./(µgL−1)). The limit of detection and limit of quantification were 4.21 ± 0.06 and 14.04 ± 0.19 µgL−1, respectively, with excellent precision (0.17 to 2.45%RSD). The accuracy in terms of recovery from spiked samples was in the range of 84 to 110% with no significant difference to a C18 cartridge. GO-Cry can be reproducibly prepared with 2.8%RSD from 4 lots and can be reused at least 10 times, which not only helps reduce the analysis costs (~0.41USD per analysis), but also reduces the resultant waste to the environment.

scholarly journals Analysis of the Chloroacetanilide Herbicides in Water Using SPME with CAR/PDMS and GC/ECD

2005 ◽  
Vol 88 (4) ◽  
pp. 1236-1241 ◽  
Author(s):  
Ying-Ming Hwang ◽  
Yih-Gang Wong ◽  
Wu-Hsiung Ho
Keyword(s):  
Humic Acid ◽  
Ph Value ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Standard Addition ◽  
Electron Capture Detection ◽  
Detection Analysis ◽  
Salt Addition ◽  
Chloroacetanilide Herbicides ◽  
Relative Standard

Abstract The solid-phase microextraction (SPME) technique using a 75 mm film of carboxen/polydimethylsiloxane was applied to the analysis of chloroacetanilide herbicides (acetochlor, alachlor, butachlor, metolachlor, and propachlor) residues. The feasibility of SPME with gas chromatography electron capture detection analysis has been evaluated. The effects of experimental parameters such as magnetic stirring, salt addition, humic acid addition, pH value, and extraction time, as well as desorption temperature and time, were investigated. Analytical parameters such as linearity, repeatability and limit of detection were also evaluated. The inhibition of humic acid to the extraction of chloroacetanilide herbicides was observed. A standard addition method for calibration was recommended to reduce deviations caused by matrix interferences. The proposed method provided a simple and rapid analytical procedure for chloroacetanilide herbicides in water with limits of detection 0.002–0.065 μg/L for deionized water, and 0.005–0.22 μg/L for farm water. The relative standard deviations (n = 5) for analyses of farm water were 7–20% for 0.5 μg/L chloroacetanilide herbicides. This application was illustrated by the analysis of sample collected from farm water in the Chung-hwa area, Taiwan.

Determination of Sulfonylurea Herbicides in Grains by Capillary Electrophoresis

1995 ◽  
Vol 78 (4) ◽  
pp. 1091-1096 ◽  
Author(s):  
Alexander J Krynitsky ◽  
Douglas M Swtneford
Keyword(s):  
Capillary Electrophoresis ◽  
Lower Limit ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Residue Analysis ◽  
High Sensitivity ◽  
Sulfonylurea Herbicides ◽  
Optical Cell ◽  
Liquid Chromatographic ◽  
Tribenuron Methyl

Abstract A capillary electrophoresis (CE) method was developed to separate and determine residues of 5 sulfonylurea herbicides in grains (wheat, barley, and corn). This work demonstrated the practicality of using CE for residue analysis of sulfonylureas. The method yielded good recoveries and adequate sensitivities at tolerance levels (0.05–0.1 ppm). The compounds investigated were metsulfuron methyl (Ally), thifensulfuron methyl (Harmony), chlorsulfuron (Glean), rimsulfuron (DPX-E9636), and tribenuron methyl (Express). Acetonitrile extracts of grain samples were partitioned with hexane and then cleaned up with cation exchange solid-phase extraction cartridges. Quantitation was performed by micellar electrokinetic capillary chromatography using a high-sensitivity optical cell. Average recoveries at the 0.05 ppm level ranged from 72.9 to 118.5%. The lower limit of detection was approximately 0.02 ppm, except for rimsulfuron and tribenuron methyl, for which the lower limit of detection was 0.035 ppm. The method was less complicated and showed better sensitivity than current single-analyte liquid chromatographic enforcement methods.

scholarly journals Solid phase selective separation and green preconcentration of Cu, Zn, Pb and Cd in drinking water by using novel functionalized resin

2009 ◽  
Vol 7 (4) ◽  
pp. 945-954 ◽  
Author(s):  
Nagwa Burham ◽  
Sami Azeem ◽  
Mohamed El-Shahat
Keyword(s):  
Drinking Water ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Exchange Capacity ◽  
Coupling Reactions ◽  
Lead And Cadmium ◽  
Sample Flow Rate ◽  
Relative Standard ◽  
Copper Zinc ◽  
Ph Range

AbstractA new solid — phase extraction sorbent was developed based on stepwise anchoring of two ligand molecules for the determination of copper, zinc, lead and cadmium in drinking water by flame AAS. Amberlite XAD-2 functionalized with 4′-(2-hydroxyphenylazo)-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one (HPAPyr) was utilized for preconcentration/separation of these elements. The sorbent was prepared by two successive azo coupling reactions. First, 2-aminophenol was anchored to the amino groups in the resin resulted from nitration followed by reduction. Then, the resulted 2-aminophenol functionalized resin was further diazotized and coupled to the pyrazolone compound and the final product HPAPyr-XAD-2 was characterized by IR and elemental analysis. The optimum pH range for sorption, shaking time, exchange capacity, sample flow rate, preconcentration factor and interference from co-existing ions were investigated. All metal ions were quantitatively desorbed from the resin by 4.5 mol L−1 nitric acid solution. The sorbent provides limit of detection within the range 0.9–3.3 µg L−1 and concentration factor up to 250. The procedure was validated by analysis of certified material NIST-SRM 1577b. Application to drinking water showed satisfactory results with relative standard deviation RSD ≤ 8.5%.

scholarly journals Determination of cyanide in bamboo shoots by microdiffusion combined with ion chromatography–pulsed amperometric detection

2018 ◽  
Vol 5 (4) ◽  
pp. 172128 ◽  
Author(s):  
Ming Ding ◽  
Kailiang Wang
Keyword(s):  
Ion Chromatography ◽  
Limit Of Detection ◽  
Correlation Coefficients ◽  
Amperometric Detection ◽  
High Sensitivity ◽  
Practical Method ◽  
Pulsed Amperometric Detection ◽  
Bamboo Shoots ◽  
Relative Standard

A practical method for the determination of cyanide in bamboo shoots has been developed using microdiffusion preparation integrated with ion chromatography–pulsed amperometric detection (IC-PAD). Cyanide was released from bamboo shoots after Conway cell microdiffusion, and then analysed by IC-PAD. In comparison with the previously reported methods, derivatization and ion-pairing agent addition were not required in this proposed microdiffusion combined with IC-PAD method. The microdiffusion parameters were optimized including hydrolysis systems, temperature, time, and so on. Under the optimum conditions, the linear range of the calibration curve for cyanide was 0.2–200.0 µg kg −1 with satisfactory correlation coefficients of 0.9996 and the limit of detection was 0.2 µg kg −1 ( S/N  = 3). The spiked recovery range was from 92.8 to 98.6%. The intra-day and inter-day relative standard deviations of cyanide were 2.7–14.9% and 3.0–18.3%, respectively. This method was proved to be convenient in operation with high sensitivity, precision and accuracy, and was successfully applied in the determination of cyanide in bamboo shoot samples.

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