scholarly journals Quantitative Determination of Acetaldehyde in Foods Using Automated Digestion with Simulated Gastric Fluid Followed by Headspace Gas Chromatography

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Michael Uebelacker ◽  
Dirk W. Lachenmeier

Acetaldehyde (ethanal) is a genotoxic carcinogen, which may occur naturally or as an added flavour in foods. We have developed an efficient method to analyze the compound in a wide variety of food matrices. The analysis is conducted using headspace (HS) gas chromatography (GC) with flame ionization detector. Using a robot autosampler, the samples are digested in full automation with simulated gastric fluid (1 h at 37°C) under shaking, which frees acetaldehyde loosely bound to matrix compounds. Afterwards, an aliquot of the HS is injected into the GC system. Standard addition was applied for quantification to compensate for matrix effects. The precision of the method was sufficient (<3% coefficient of variation). The limit of detection was 0.01 mg/L and the limit of quantification was 0.04 mg/L. 140 authentic samples were analyzed. The acetaldehyde content in apples was  mg/kg, orange juice contained  mg/kg. The highest concentration was determined in a yoghurt (17 mg/kg). A first-exposure estimation resulted in a daily acetaldehyde intake of less than 0.1 mg/kg bodyweight from food, which is considerably lower than the exposures from alcohol consumption or tobacco smoking.

2018 ◽  
Vol 16 (1) ◽  
pp. 81-93
Author(s):  
MDH Prodhan ◽  
SN Alam

Determination of organochlorine pesticide residues in shrimp is very important to ensure the consumer’s safety and to fulfill the importer’s demand. Therefore, a simple and efficient multiple organochlorine pesticide residues analytical method using quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction technique and Gas Chromatography coupled with Electron Capture Detector (ECD) has been developed and validated for the determination of 19 organochlorine pesticides (α- BHC, δ- BHC, β- BHC, γ- BHC, Heptachlor, Aldrin, Heptachlor Epoxide, γ- Chlordane, α- Chlordane, α- Endosulfan, 4,4 DDE, Dieldrin, Endrin, 4,4 DDD, β- Endosulfan, 4,4 DDT, Endosulfan sulphate, Methoxychlor, and Endrin Ketone) in shrimp. The method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD) and limit of quantification (LOQ). The average recoveries of the selected pesticides ranged from 84% to 106% with RSDr ≤ 14% in four fortification levels of 0.05, 0.1, 0.2 and 0.3 mg kg-1. The linearity was ≥ 0.996 for all of the selected pesticides with matrix matched calibration standards. The LOD ranged from 0.003 to 0.009 mg kg-1 and the LOQ was 0.05 mg kg-1. This method was applied successfully for the residue analysis of 40 shrimp samples collected from different regions in Bangladesh.SAARC J. Agri., 16(1): 81-93 (2018)


Author(s):  
HARMITA HARMITA ◽  
HERMAN SURYADI ◽  
LIDWINA DEVIANI LIKASA

Objective: The purpose of this research was to optimize and validate a method for measuring the levels of diallyl disulfide (DADS) and diallyl trisulfide(DATS) in garlic and single clove garlic.Methods: The analysis was performed using gas chromatography (GC) equipped with an HP-1 column and a flame ionization detector. The initialcolumn temperature was set at 140°C and increased at 1°C/min to 180°C. The injector and detector temperatures were set to 200°C, the carrier gasflow rate was 0.80 mL/min, and the injection volume was 1.0 μL. The optimized conditions of analysis were then validated which included selectivity,linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ).Results: Using the validated assay and a concentration range of 0.5–20 μg/mL, the coefficient of correlation (r) for DADS was 0.9999 and the LODand LOQ for DADS were 0.3063 μg/mL and 1.0210 μg/mL, respectively. Using the validated assay and a concentration range of 0.5–20 μg/mL, thecoefficient of correlation for DATS was 0.9999 and the LOD and LOQ for DATS were 0.1986 μg/mL and 0.6621 μg/mL, respectively. The percentage ofrecovery was in the range of 98.05–101.76% and coefficient of variation ≤ 2%.Conclusion: This GC method accurately measures the levels of DADS and DATS in garlic.


1988 ◽  
Vol 71 (4) ◽  
pp. 729-731
Author(s):  
Paul Aitkenhead ◽  
Arne Vidnes

Abstract A simple and accurate method is described for the determination of ethylene chlorohydrin (ECH) by using capillary gas chromatography (GC) and flame ionization detection. Acetonitrile-methanol was chosen as the extraction solvent in preference to other solvents because its use reduced the number of compounds detected by the GC system, thus enabling easier identification and quantitation of ECH. The coefficient of variation for the method is 2.7% at 5 ppm, and recovery is good, even for the standard addition of 1 ppm. Fifteen different spices and condiments were analyzed using this method; 20% were identified as positive for ECH. The method also identifies the related compound ethylene bromohydrin (EBH).


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6914
Author(s):  
Maria Suely Siqueira Ferraz ◽  
Lêda Rita D’Antonino Faroni ◽  
Fernanda Fernandes Heleno ◽  
Adalberto Hipólito de Sousa ◽  
Lucas Henrique Figueiredo Prates ◽  
...  

Bioinsecticides are regarded as important alternatives for controlling agricultural pests. However, few studies have determined the persistence of these compounds in stored grains. This study aimed at optimizing and validating a fast and effective method for extraction and quantification of residues of safrole (the main component of Piper hispidinervum essential oil) in cowpea beans. It also sought to assess the persistence of this substance in the grains treated by contact and fumigation. The proposed method used headspace solid-phase microextraction (HS-SPME) and gas chromatography with a flame ionization detector (GC/FID). Factors such as temperature, extraction time and type of fiber were assessed to maximize the performance of the extraction technique. The performance of the method was appraised via the parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. The LOD and LOQ of safrole were 0.0057 and 0.019 μg kg−1, respectively and the determination coefficient (R2) was >0.99. The relative recovery ranged from 99.26 to 104.85, with a coefficient of variation <15%. The validated method was applied to assess the persistence of safrole residue in grains, where concentrations ranged from 1.095 to 0.052 µg kg−1 (contact) and from 2.16 to 0.12 µg kg −1 (fumigation). The levels measured up from the fifth day represented less than 1% of the initial concentration, proving that safrole have low persistence in cowpea beans, thus being safe for bioinsecticide use. Thus, this work is relevant not only for the extraction method developed, but also for the possible use of a natural insecticide in pest management in stored grains.


Toxins ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 406 ◽  
Author(s):  
Leticia Díez-Quijada ◽  
Remedios Guzmán-Guillén ◽  
Ana Prieto Ortega ◽  
María Llana-Ruíz-Cabello ◽  
Alexandre Campos ◽  
...  

Cyanotoxins are a large group of noxious metabolites with different chemical structure and mechanisms of action, with a worldwide distribution, producing effects in animals, humans, and crop plants. When cyanotoxin-contaminated waters are used for the irrigation of edible vegetables, humans can be in contact with these toxins through the food chain. In this work, a method for the simultaneous detection of Microcystin-LR (MC-LR), Microcystin-RR (MC-RR), Microcystin-YR (MC-YR), and Cylindrospermopsin (CYN) in lettuce has been optimized and validated, using a dual solid phase extraction (SPE) system for toxin extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for analysis. Results showed linear ranges (5–50 ng g−1 f.w.), low values for limit of detection (LOD) (0.06–0.42 ng g−1 f.w.), and limit of quantification (LOQ) (0.16–0.91 ng g−1 f.w.), acceptable recoveries (41–93%), and %RSDIP values for the four toxins. The method proved to be robust for the three variables tested. Finally, it was successfully applied to detect these cyanotoxins in edible vegetables exposed to cyanobacterial extracts under laboratory conditions, and it could be useful for monitoring these toxins in edible vegetables for better exposure estimation in terms of risk assessment.


2018 ◽  
Vol 34 (2(96)) ◽  
pp. 133-143
Author(s):  
Agnieszka Woźnica

1,2-Dichloroethane is a colorless, highly flammable liquid with a chloroform-like odor. This substance is used in industry as an intermediate in the production of vinyl chloride, but it is also used in the production of other chlorinated hydrocarbons. It is also used as a solvent. 1,2-Dichloroethane is carcinogenic for humans. The aim of this study was to develop a method for determining concentrations of 1,2-dichloroethane in the workplace air in the range from 1/10 to 2 MAC values (0.82–16.4 mg/m3). The study was performed using a gas chromatograph (GC) with a flame ionization detector (FID) equipped with a capillary column HP-1 (50 m x 0.32 mm; 0.3 μm). The method is based on the adsorption of 1,2-dichloroethane on activated charcoal, desorption of analyzed compound with carbon disulfide and analysis of obtained solution with GC-FID. The use of HP-1 column enabled selective determination of 1,2-dichloroethane in a presence of other substances. The average desorption coefficient of 1,2-dichloroethane from charcoal was 0.98. The method is linear (r = 0.9999) within the investigated working range from 9.84 to 196.8 μg/ml, which is equivalent to air concentrations from 0.82 to 16.4 mg/m3 for a 12-L air sample. The limit of detection (LOD) and limit of quantification (LOQ) were to 2.284 μg/ml and 6.85 μg/ml, respectively. The analytical method described in this paper enables selective determination of 1,2-dichloroethane in workplace air in presence of other substances at concentrations from 0.82 mg/m3 (1/10 MAC value). The method is precise, accurate and it meets the criteria for procedures for measuring chemical agents listed in Standard No. EN 482. The method can be used for assessing occupational exposure to 1,2-dichloroethane and associated risk to workers’ health. The developed method of determining 1,2-dichloroethane has been recorded as an analytical procedure (see appendix).


Author(s):  
MUCHTARIDI MUCHTARIDI ◽  
Kurnia Megawati ◽  
Febrina Amelia Saputri ◽  
Mulyana Mulyana

Objective: The purpose of this study was to obtain a valid analytical method for determining the level of 2,5-hexanedione in the urine of oil industry workers. Methods: Gas Chromatography (GC) was employed to analyze 2,5-hexanedione in the urine. The analysis was done using HP-5 (Crosslinked methyl siloxane) capillary columns 30 m x 0.320 mm long, film thickness 0.25 μm. The temperature of the detector temperature was 300 °C, and the injector temperature was 250 °C. The helium gas flow rate was 2 ml/min. The detector was Flame Ionization Detection (FID). Parameters of system suitability test and validation were obtained. Results: This study results that the method of analysis 2,5-hexanedione in urine by Gas Chromatography (GC) confirm the requirements of the validation method with a linearity was 0.99963, accuracy was in the range of 99.16% to 114.13%, the precision with % coefficient of variation was 1.65% to 5.16%, % coefficient variation of specificity was 0.027%, limit of detection was 0.054 μg/ml and limit of quantification was 0.18 μg/ml. Conclusion: The proposed GC method meets the acceptance criteria of validation parameters and can be applied for routine analysis.


2011 ◽  
Vol 17 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Zenita Devi ◽  
K. Basavaiah ◽  
K.B. Vinay

Three simple and sensitive spectrophotometric methods are described for the determination of domperidone (DOM) in bulk drug and in dosage forms using bromate-bromide mixture as brominating agent in acid medium and three dyes, meta-cresol purple (MCP), amaranth (AMR) and erioglaucine (EGC). The methods involve the addition of a known excess of bromate-bromide mixture to an acidified solution of DOM followed by the determination of the residual bromine by reacting with a fixed amount of either MCP dye and measuring the absorbance at 530 nm (method A) or AMR dye and measuring the absorbance at 520 nm (method B) or EGC dye and measuring the absorbance at 630 nm (method C). Beer?s law is obeyed over the concentration ranges, 0.63 - 10.0, 0.25-4.0 and 0.13-2.0 ?g mL-1 for method A, method B and method C, respectively. The apparent molar absorptivities are calculated to be 3.751 ? 104, 6.604 ? 104 and 1.987 ? 105 L mol-1cm-1 for method A, method B and method C, respectively and the corresponding sandell sensitivity values are 0.011, 0.006 and 0.002 ?g cm-2. The limit of detection and the limit of quantification are also reported for all the three methods. No interference was observed from common additives found in pharmaceutical preparations. Statistical comparisons of the results with those of the reference method showed an excellent agreement, and indicated no significant difference in accuracy and precision. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard-addition technique.


2020 ◽  
Author(s):  
Zehra Hajrulai-Musliu ◽  
Risto Uzunov ◽  
Stefan Jovanov ◽  
Dean Jankuloski ◽  
Velimir Stojkovski ◽  
...  

Abstract A multi-class and multi-residue/contaminant method for the determination of veterinary drug and pesticide residues and mycotoxins in bovine meat has been developed and validated. The veterinary drug residues/contaminants included antimicrobials, anabolic hormones, lactones, β-agonists, mycotoxins, and pesticides. Isotopic labeled internal standards were included to compensate residual matrix effects. The calibrators used in the method demonstrated linearity with the coefficient of correlation (R2) > 0.98. The decision limit (CCα) values were in the range from 0.067 to 2103.84 μg/kg, while the range for detection capability (CCβ) was from 0.083 to 2482.13 μg/kg. The limit of detection (LOD) and limit of quantification (LOQ) were in the range from 0.059 to 291.36 μg/kg, and 0.081 to 328.13 μg/kg, respectively. The recovery of analytes ranged from 61.28 % to 116.20 %. The intra-day coefficient of variation (CV) was from 0.97 to 25.93 % and the inter-day CV was 2.30-34.04 %. The method has been used for the determination of 49 residues/contaminants in bovine meat.


Author(s):  
Hien Dang Thu ◽  
Ngoc Anh Mai Thi ◽  
Hong Ngoc Nguyen Thi ◽  
◽  
◽  
...  

In this study, a method for determination of six phytosterols by gas chromatography-mass spectrometry with derivatization in vegetable oils was validated. The samples were hydrolyzed in an alkaline media at 70&deg;C for 60 min. Then, the samples were performed liquid-liquid extraction with toluene. The phytosterols are derivatized to trimethylsilyl ethers and then analyzed by gas chromatography-mass spectrometry. The limit of detection and limit of quantification was 5 and 15 mg/kg, respectively. Recoveries of six phytosterols were between 93.5% and 101%.


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