Measuring the Phthalates of Xiangjiang River Using Liquid-Liquid Extraction Gas Chromatography

2011 ◽  
Vol 301-303 ◽  
pp. 752-755 ◽  
Author(s):  
Xiao Juan Zhu ◽  
Yin Yan Qiu
Keyword(s):  
Gas Chromatography ◽  
Water Environment ◽  
Liquid Extraction ◽  
Dioctyl Phthalate ◽  
Optimum Conditions ◽  
Xiangjiang River ◽  
Chromatography Method ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Ethylhexyl Phthalate

Objective: To observe the phthalates pollution situation in water environment and design the liquid-liquid extraction gas chromatography method to measure phthalates in Xiangjiang River water. Methods: The water samples were collected from six monitor points of the Xiangjiang River’s Changsha period. After liquid-liquid extraction, gas chromatography was used to measure and analyze the phthalates pollution in this period of the river. Results: Dioctyl phthalate resin (DOP) and dibutyl phthalate (2- ethylhexyl) phthalate (DEHP) were detectable in all samples from six monitor points, the concentrations of DEHP were from 0.62-15.23μg/L, DOP were from 0.04-0.21μg/L. Conclusion: The optimum conditions for the extraction of phthalates are: 0.025ml dichloromethane as extraction solvent, centrifuge speed at 4000r/min, extraction time 20 minutes, and this method is appropriate for monitoring the phthalates pollution in water environment.

scholarly journals MINIATURIZED LIQUID-LIQUID EXTRACTION WITH LOW-TEMPERATURE PARTITIONING TECHNIQUE (LLE/LTP) FOR PESTICIDE ANALYSIS IN A BIOLOGICAL MATRIX BY GAS CHROMATOGRAPHY

Química Nova ◽  
2021 ◽  
Author(s):  
Thaís Silva ◽  
Maria Eliana Queiroz ◽  
Antônio Neves ◽  
Patrícia Vieira ◽  
André Oliveira ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Low Temperature ◽  
Blood Serum ◽  
Liquid Extraction ◽  
Serum Samples ◽  
Biological Matrix ◽  
Rural Workers ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Partitioning Technique

The liquid-liquid extraction with low-temperature partitioning technique (LLE/LTP) was miniaturized to determine the pesticides chlorpyrifos, bifenthrin, λ-cyhalothrin, and deltamethrin in a biological matrix, by gas chromatography. The method was proposed for fetal-bovine serum samples (500 μL), by using a full factorial design (23) with one center point. The evaluated factors included the volume of water added to the sample (1000 μL), volume of extraction solvent (500 μL) and stirring time (60 s) – a cleanup step was not necessary. The method was validated for the main figures of merit. The results indicated that the LLE/LTP/GC/ECD miniaturized method was efficient in extracting pesticides from blood-serum samples (75 to 115%). It showed both selectivity and sensitiveness, with limits of quantification (LOQ) ranging from 8 at 17 μg L-1. Once validated, the method was applied to blood-serum samples of rural workers from a city in the Brazilian state of Minas Gerais. In that case, the presence of chlorpyrifos was detected in two of the samples.

scholarly journals Optimization and validation of the salting-out assisted liquid-liquid extraction method and analysis by gas chromatography to determine pesticides in water

2018 ◽  
Vol 43 (1SI) ◽  
pp. 11
Author(s):  
Alessandra Aparecida Zinato Rodrigues ◽  
Antônio Augusto Neves ◽  
Maria Eliana Lopes Ribeiro De Queiroz ◽  
André Fernando De Oliveira ◽  
Lucas Henrique Figueiredo Prates ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Single Phase ◽  
Limit Of Detection ◽  
Liquid Extraction ◽  
Solvent Ratio ◽  
Limit Of Quantification ◽  
Salting Out ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Pesticides In Water

The salting-out assisted liquid-liquid extraction (SALLE) was developed for the analysis of four pesticides (cypermethrin, chlorpyrifos, deltamethrin, and thiamethoxam) in water samples. For its optimization, a 2³ factorial design was used to evaluate the simultaneous behavior of three factors: sample and extraction solvent ratio, saline concentration, and stirring mode. A 1.0 mL saline solution (NaCl) was added to the single-phase mixture of water and extraction solvent to separate the phases. The mixture was stirred, allowed to stand and the top organic phase containing the pesticides of interest was analyzed by gas chromatography coupled with electron capture detector (GC/ECD). The optimized method was validated for some merit figures. The limit of detection of the method ranged from 0.15 to 5.5 µg L-1 and the limit of quantification from 5.5 to 18.2 µg L-1. The method showed satisfactory results for the linearity (R2 ≥ 0,990), precision (CV < 9 %) and accuracy (72 % ≤ recovery ≤ 90 %) for all the assessed analytes. The method showed to be simple, efficient and inexpensive for the extraction of pesticide residues. The validated method was applied to ten samples of water collected in the Zona da Mata region of the state of Minas Gerais, Brazil.

A Novel Liquid–Liquid Extraction for the Determination of Nicotine in Tap Water, Wastewater, and Saliva at Trace Levels by GC-MS

2016 ◽  
Vol 99 (3) ◽  
pp. 806-812 ◽  
Author(s):  
Joanna Sonia Dobrowska ◽  
Sezin Erarpat ◽  
Dotse Selali Chormey ◽  
Krystyna Pyrzyńska ◽  
Sezgin Bakirdere
Keyword(s):  
Analytical Method ◽  
Tap Water ◽  
Internal Standard ◽  
Liquid Extraction ◽  
Calibration Plot ◽  
Optimum Conditions ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Extraction Period

Abstract Determination of nicotine at trace levels in different matrixes is crucial because of nicotine's strongly addictive property. In this study, a simple and fast analytical method was developed using liquid–liquid extraction with GC-MS. Chloroform was used as an extraction solvent. Different parameters for extraction, such as pH of the solution, types and volumes of extraction and supporter solvents for dispersion, extraction period, and salt type and its amount, were optimized. To improve the precision, naphthalene was used as an internal standard. The calibration plot of nicotine was linear from 0.010 to 2.0 mg/L with a correlation coefficient 0.9996. The LOD and LOQ for nicotine after extraction were 2.6 and 8.8 ng/mL, respectively. Under the optimum conditions, tap water, wastewater, and saliva samples were analyzed for their nicotine content. The spiking experiments yielded satisfactory recoveries of 97.6 ± 3.5, 96.8 ± 1.1, and 85.1 ± 1.3% for tap water, wastewater, and saliva samples, respectively.

scholarly journals Lipemia in the Plasma Sample Affects Fentanyl Measurements by Means of HPLC-MS2 after Liquid-Liquid Extraction

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4514
Author(s):  
Marta Tikhomirov ◽  
Tomasz Śniegocki ◽  
Błażej Poźniak
Keyword(s):  
Forensic Toxicology ◽  
Liquid Extraction ◽  
Rabbit Plasma ◽  
Chromatography Method ◽  
Method Performance ◽  
Liquid Liquid Extraction ◽  
Normal Plasma ◽  
Validation Procedure ◽  
Liquid Chromatography Method ◽  
The Impact

Examination of fentanyl levels is frequently performed in certain scientific evaluations and forensic toxicology. It often involves the collection of very variable blood samples, including lipemic plasma or serum. To date, many works have reported the methods for fentanyl detection, but none of them have provided information about the impact on the assay performance caused by an excessive amount of lipids. This aspect may be, however, very important for highly lipophilic drugs like fentanyl. To address this issue, we developed the liquid chromatography method with mass spectrometry detection and utilized it to investigate the impact of lipids presence in rabbit plasma on the analytical method performance and validation. The validation procedure, conducted for normal plasma and lipemic plasma separately, resulted in good selectivity, sensitivity and linearity. The limits of detection and quantification were comparable between the two matrices, being slightly lower in normal plasma (0.005 and 0.015 µg/L) than in lipemic plasma (0.008 and 0.020 µg/L). Liquid–liquid extraction provided a low matrix effect regardless of the lipid levels in the samples (<10%), but pronounced differences were found in the recovery and accuracy. In the normal plasma, this parameter was stable and high (around 100%), but in the lipemic matrix, much more variable and less efficient results were obtained. Nevertheless, this difference had no impact on repeatability and reproducibility. In the present work, we provided reliable, convenient and sensitive method for fentanyl detection in the normal and lipemic rabbit plasma. However, construction of two separate validation curves was necessary to provide adequate results since the liquid-liquid extraction was utilized. Therefore, special attention should be paid during fentanyl quantification that involves lipemic plasma samples purified by this technique.

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