scholarly journals The Use of Single Drop Microextraction and Field Amplified Sample Injection for CZE Determination of Homocysteine Thiolactone in Urine

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5687
Author(s):  
Krystian Purgat ◽  
Izabella Kośka ◽  
Paweł Kubalczyk
Keyword(s):  
Calibration Curve ◽  
Phosphate Buffer ◽  
Fused Silica ◽  
Effective Length ◽  
Single Drop ◽  
Homocysteine Thiolactone ◽  
Sample Injection ◽  
Single Drop Microextraction ◽  
Relative Standard

Two cheap, simple and reproducible methods for the electrophoretic determination of homocysteine thiolactone (HTL) in human urine have been developed and validated. The first method utilizes off-line single drop microextraction (SDME), whereas the second one uses off-line SDME in combination with field amplified sample injection (FASI). The off-line SDME protocol consists of the following steps: urine dilution with 0.2 mol/L, pH 8.2 phosphate buffer (1:2, v/v), chloroform addition, drop formation and extraction of HTL. The pre-concentration of HTL inside a separation capillary was performed by FASI. For sample separation, the 0.1 mol/L pH 4.75 phosphate buffer served as the background electrolyte, and HTL was detected at 240 nm. A standard fused-silica capillary (effective length 55.5 cm, 75 μm id) and a separation voltage of 21 kV (~99 μA) were used. Electrophoretic separation was completed within 7 min, whereas the LOD and LOQ for HTL were 0.04 and 0.1 μmol/L urine, respectively. The calibration curve in urine was linear in the range of 0.1–0.5 μmol/L, with R2 = 0.9991. The relative standard deviation of the points of the calibration curve varied from 2.4% to 14.9%. The intra- and inter-day precision and recovery were 6.4–10.2% (average 6.0% and 6.7%) and 94.9–102.7% (average 99.7% and 99.5%), respectively. The analytical procedure was successfully applied to the analysis of spiked urine samples obtained from apparently healthy volunteers.

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.

Determination of Volatile Halogenated Hydrocarbons in Wastewater by Single-Drop Microextraction Coupled to Capillary Gas Chromatography

2013 ◽  
Vol 295-298 ◽  
pp. 487-491
Author(s):  
Jian Qi Sun
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Halogenated Hydrocarbons ◽  
Wastewater Sample ◽  
Single Drop ◽  
Single Drop Microextraction ◽  
Relative Standard ◽  
Wastewater Samples ◽  
Volatile Halogenated Hydrocarbons

Single-drop microextraction (SDME) coupled to capillary gas chromatography (GC) was established for the determination of seven volatile halogenated hydrocarbons in wastewater, including chloroform (CF), carbon tetrachloride (CT), trichloroethylene (TCE), bromodichloromethane (BDCM), perchlorethylene (PCE), dibromochloromethane (DBCM) and bromoform (BF). The SDME parameters such as extractants, extracting time，stirring rate and immerging depth of needle point were studyed and optimized. The abovementioned halogenated hydrocarbons were quantified by external standardization method using GC coupled with a flame ionization detector (FID). The linear regression calibration curves, detection limits (S/N=3) and the linear ranges of the method for determining each halogenated hydrocarbons were determined, respectively. The concentrations of componds abovementioned in a real wastewater sample, the average of the recoveries obtained in the spiked wastewater samples and the corresponding relative standard deviations were determined, respectively. The results showed the proposed method several attributes, friendly enviroment, economic and highly efficient pretreatment, less time, simplicity, sensitivity, accuracy and wide linear range and so on.

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

2013 ◽  
Vol 295-298 ◽  
pp. 483-486 ◽  
Author(s):  
Jian Qi Sun
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Phthalate Esters ◽  
Wastewater Sample ◽  
Single Drop ◽  
Flame Ionization ◽  
Single Drop Microextraction ◽  
Relative Standard ◽  
Wastewater Samples

Single-drop microextraction (SDME) coupled to capillary gas chromatography (GC) was established for the determination of four phthalate esters in wastewater, including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-octyl phthalate (DnOP) and butyl benzyl phthalate (BBP). The SDME parameters such as extractants, extracting time，stirring rate and immerging depth of needle point were studyed and optimized. The abovementioned phthalate esters were quantified by external standardization method using GC coupled with a flame ionization detector (FID). The linear regression calibration curves, detection limits (S/N=3) and the linear ranges of the method for determining each phthalate were determined, respectively. The concentrations of components abovementioned in a real wastewater sample, the average of the recoveries obtained in the spiked wastewater samples and the corresponding relative standard deviations were determined, respectively. The results showed the proposed method several attributes, friendly enviroment, economic and highly efficient pretreatment, less time, simplicity, sensitivity, accuracy and wide linear range and so on.

scholarly journals Simultaneous Separation of 14 Antiarrhythmic Drugs and Determination of Mexiletine and Flecainide by Capillary Zone Electrophoresis

2007 ◽  
Vol 90 (4) ◽  
pp. 977-986 ◽  
Author(s):  
Rafal Pietra ◽  
Dorota Kowalczuk ◽  
Hanna Hopkala
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Applied Voltage ◽  
Antiarrhythmic Drugs ◽  
Fused Silica ◽  
Effective Length ◽  
Relative Standard ◽  
Simultaneous Separation ◽  
Zone Electrophoresis ◽  
Capillary Zone

Abstract A method using capillary zone electrophoresis was developed for the simultaneous separation of 14 antiarrhythmic drugs belonging to various classes. The drugs are separated on a fused-silica capillary, 90 cm 75 m (72 cm effective length), with phosphate and acetate buffers as background electrolytes and UV detection at 217 nm. The effects of buffer pH, temperature, and applied voltage on the migration of the drugs were studied. The pH was found to be the most significant factor determining effective separation. The antiarrhythmic compounds are completely separated within a relatively short time (<7 min) by using 70 mM phosphate buffer at pH 7.91, an applied voltage of 28 kV, and a temperature of 32C. Mexiletine (MEX) and flecainide (FLE) were quantified under conditions of the optimum separation. The calibration graphs were constructed over the concentration range of 4.014.0 g/mL for both drugs with good correlation (r 0.9999). Detection and quantitation limits were found to be 0.5 and 1.5 g/mL for FLE and 0.7 and 2.1 g/mL for MEX, respectively. The proposed method was used for the determination of both drugs in their commercial forms with satisfactory precision (relative standard deviations of 0.361.21% for FLE and 0.781.66% for MEX) and accuracy (relative standard errors of 0.131.17% for FLE and 0.351.18% for MEX).

Determination of Polycyclic Aromatic Hydrocarbons in Wastewater by Single-Drop Microextraction Coupled to Capillary Gas Chromatography

2013 ◽  
Vol 838-841 ◽  
pp. 2582-2585 ◽  
Author(s):  
Jian Qi Sun ◽  
Bo Qiao ◽  
De Si Sun
Keyword(s):  
Gas Chromatography ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Capillary Gas Chromatography ◽  
Preparation Technique ◽  
Single Drop ◽  
Single Drop Microextraction ◽  
Relative Standard ◽  
Polycyclic Aromatic

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 polycyclic aromatic hydrocarbons (PAHs) in wastewater, including naphthalene, 1-naphthol, 2-naphthol and anthracene. 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 investigated and optimized. The method was linear in the ranges from 2.3 ×10-3to 70.0 μg·mL-1for naphthalene, 1-naphthol and anthracene, and 2.2 ×10-3to 50.0 μg·mL-1for 2-naphthol withR2≥ 0.9990. The SDME procedure allowed efficient recovery of the investigated PAHs ranging between 94 % and 104 % with a relative standard deviation (RSD) ≤4.2 for actual wastewater sampes spiked with 5, 10 and 20 μg·mL-1of PAHs, respectively. These results showed the potential of this technique for PAHs monitoring in wastewater samples. Furthermore, the investigated methods are simple, reliable, reproducible, and not expensive.

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