scholarly journals the Extraction and determination of benzene from waters and wastewater samples based on functionalized carbon nanotubes by static head space gas chromatography mass spectrometry

2020 ◽  
Vol 3 (01) ◽  
pp. 17-26
Author(s):  
Shahnaz Teimoori ◽  
Amir Hessam Hassani *© ◽  
Mostafaa Panaahie
Keyword(s):  
Carbon Nanotubes ◽  
Water Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Maximum Adsorption Capacity ◽  
Static System ◽  
Benzene Removal ◽  
Wastewater Samples ◽  
Static Head ◽  
Modified Carbon Nanotubes

In this study, the phenyl sulfonic acid (PhSA) modified carbon nanotubes (CNTs) were used for benzene removal from waters by  (D- μSPE). Due to adsorption mechanism, π–π interactions was provided between the aromatic ring of benzene with the surface (SO3H) and phenyl ring (-C6H5) of CNTs, respectively. Therefore, 20-100 mg of sorbent, concentration of benzene (0.1–10 mg L-1), pH (1-12) and contact time (5–120 min) were investigated and optimized for benzene removal from water samples in static system. The concentration of benzene in water was determined by (SHS-GC-MS). The results showed, the Langmuir-Freundlich (LF) isotherm provided the best fit for benzene sorption. By using the Langmuir model, the maximum adsorption capacity of 117.34 and 22.86 mg/g was achieved for benzene removal from waters with CNTs@PhSA and CNTs, respectively. Under optimal conditions, adsorption efficiency of CNTs@PhSA and CNTs was obtained 97.7% and 20.6 % for benzene removal from water samples, respectively. 

Determination of 3,3'-Dichlorobenzidine in Industrial Wastewaters

2004 ◽  
Vol 39 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Hing-Biu Lee ◽  
Thomas E. Peart ◽  
Ken Terry ◽  
James Maguire
Keyword(s):  
Electron Impact ◽  
Chemical Ionization ◽  
Solid Phase ◽  
Negative Ion ◽  
Gas Chromatography Mass Spectrometry ◽  
Ms Detection ◽  
Negative Ion Chemical Ionization ◽  
Ionization Mode ◽  
Wastewater Samples

Abstract A solid-phase extraction, chemical derivatization, and gas chromatography/mass spectrometry (GC/MS) method has been developed for the determination of trace 3,3'-dichlorobenzidine (DCB) in industrial wastewater samples. Instead of an octadecylsilane (ODS) cartridge, a Porapak RDX cartridge was used since the latter could be optimized for the extraction of DCB. After the pre-concentration, interfering coextractives in the sample were selectively removed from the cartridge by elution with a 1:1 mixture of acetonitrile and water. DCB was then eluted with acetonitrile and derivatized with pentafluoropropionic acid anhydride. The product was subsequently analyzed by GC/MS in either the electron impact or negative ion chemical ionization mode. Recoveries of DCB and the surrogate, DCB-d6, were better than 90% at spiking levels of 10, 1, and 0.1 µg/L. Based on a concentration factor of 100, the detection limits for DCB in wastewater samples were determined to be 0.1 µg/L by electron impact GC/MS detection, and 0.01 µg/L by negative ion chemical ionization GC/MS detection, respectively. This method has been successfully applied to wastewater samples collected in the Toronto area.

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