scholarly journals Determination of Pesticide Residues in Honey by Single-Drop Microextraction and Gas Chromatography

2011 ◽  
Vol 94 (2) ◽  
pp. 634-644 ◽  
Author(s):  
Nikolaos G Tsiropoulos ◽  
Elpiniki G Amvrazi
Keyword(s):  
Pesticide Residues ◽  
Enrichment Factors ◽  
The European Union ◽  
Maximum Residue Limit ◽  
Single Drop ◽  
Limit Values ◽  
Screening Design ◽  
Single Drop Microextraction ◽  
Central Composite

Abstract A novel, simple, and rapid single-drop microextraction (SDME) procedure combined with GC has been developed, validated, and applied for the determination of multiclass pesticide residues in honey samples. The SDME was optimized using a Plackett-Burman screening design considering all parameters that may influence an SDME procedure and a consequent central composite design to control the parameters that were found to significantly influence the pesticide determination. The developed analytical method required minimal volumes of organic solvents and exhibited good analytical characteristics with enrichment factors ranging from 3 for -endosulfan to 10 for lindane, procymidone, and captan and method quantification limits ranging from 0.03 g/kg for phosalone to 10.6 g/kg for diazinon. The relative recoveries obtained ranged from 70.8 for captan to 120 for fenarimol, and the precision (RSD) ranged from 3 to 15. The proposed SDME procedure followed by GC with an electron capture detector for quantification and GC/MS for identification was applied with success to the analysis of 17 honey samples. Monitoring results indicated a low level of honey contamination by diazinon, chlorpyrifosethyl, procymidone, bromopropylate, and endosulfan (-, -, and endosulfan sulfate) residues that were far below the maximum residue limit values specified by the European Union for endosulfan (10 g/kg) and bromopropylate (100 g/kg) in honey samples.

Determination of Chlorobenzenes in Wastewater by Single-Drop Microextraction Coupled to Capillary Gas Chromatography

2013 ◽  
Vol 838-841 ◽  
pp. 2566-2569
Author(s):  
Jian Qi Sun ◽  
Bo Qiao ◽  
Jun Dai
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Preparation Technique ◽  
Single Drop ◽  
Flame Ionization ◽  
Single Drop Microextraction ◽  
Relative Standard ◽  
Efficient Recovery ◽  
Wastewater Samples

This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of chlorobenzenes (m-dichlorobenzene (m-DCB),p-dichlorobenzene (p-DCB),o-dichlorobenzene (o-DCB) and 1,2,4-trichlorobenzene (1,2,4-TCB)) in wastewater. For this purpose, single-drop microextraction (SDME) was applied as a sample preparation technique. The SDME parameters such as types of extractants, volume of the microdroplet size, extraction time, stir rate and immersion depth of needle point were studyed and optimized. The method was linear in the ranges from 4.0×10-3to 40.0 μg·mL-1form-DCB,p-DCB ando-DCB, and 4.0×10-3to 30.0 μg·mL-1for 1,2,4-TCB withR2≥0.9955. The SDME procedure allowed efficient recovery of the investigated chlorobenzenes ranging between 80 % and 105 % with a relative standard deviation (RSD) ≤6.5 for actual wastewater sampes spiked with 2, 5 and 10 μg·mL-1of chlorobenzes, respectively. These results showed the potential of this technique for chlorobenzenes monitoring in wastewater samples. Furthermore, the investigated methods are simple, reliable, reproducible, and not expensive.

scholarly journals Collective Ion-Pair Single-Drop Microextraction Attenuated Total Reflectance Fourier Transform Infrared Spectroscopic Determination of Perchlorate in Bioenvironmental Samples

2018 ◽  
Vol 101 (4) ◽  
pp. 1145-1155 ◽  
Author(s):  
Swati Chandrawanshi ◽  
Santosh K Verma ◽  
Manas K Deb
Keyword(s):  
Ftir Spectroscopy ◽  
Ion Pair ◽  
Attenuated Total Reflectance ◽  
Sodium Iodide Symporter ◽  
Single Drop ◽  
Total Reflectance ◽  
Calibration Curves ◽  
Single Drop Microextraction ◽  
Perchlorate Concentration

Abstract Perchlorate (ClO4−) is an environmental pollutant that affects human health. Perchlorate acts as a competitive inhibitor of iodine uptake in the thyroid gland (sodium–iodide symporter inhibitor); thus, its determination is important for public health concerns. Water and milk constitute a significant portion of the human diet. Because regular intake leads to an increase in perchlorate concentration in the human body, the estimation of perchlorate is of great concern. In this work, ion-pair single-drop microextraction (SDME) combined with attenuated total reflectance (ATR)-FTIR spectroscopy has been developed for the determination of perchlorate in bioenvironmental (soil, water, dairy milk, breast milk, and urine) samples. Perchlorate was extracted in a single drop of methyl isobutyl ketone as an - with the cationic surfactant cetyltrimethylammonuim bromide under optimized conditions. The strongest IR peak (at 1076 cm−1) was selected for the quantification of perchlorate among three observed vibrational peaks. Eight calibration curves for different concentration ranges of perchlorate were prepared, and excellent linearity was observed for absorbance and peak area in the range of 0.03–100 ng/mL perchlorate, with r values of 0.977 and 0.976, respectively. The RSDs (n = 8) for the perchlorate concentration ranges of 0.03–100, 0.03–0.5, 0.5–10, and 10–100 ng/mL were in the range of 1.9–2.7% for the above calibration curves. The LOD and LOQ in the present work were 0.003 and 0.02 ng/mL, respectively. The extracted microdrop was analyzed directly by ATR-FTIR spectroscopy. The parameters affecting SDME, i.e, effect of pH, stirring rate, reagent concentration, microdrop volume, and extraction time, were optimized, and the role of foreign species was also investigated. F- and t-tests were performed to check the analytical QA of the method. A noteworthy feature of the reported method is the noninterference of any of the associated ions. The results were compared with those of the ion chromatography MS method, and a high degree of acceptability was found. The method was successfully applied for the determination of perchlorate in bioenvironmental samples.

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