Ahmad Makahleh

Dr. Ahmad Makahleh

orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 December 2019 in Arabian Journal of Chemistry
Verified
Journal Article
Open access
HSHaizarul Aida Sapahin
Haizarul Aida Sapahin
AMAhmad Makahleh
Ahmad Makahleh
BSBahruddin Saad
Bahruddin Saad
An adequate and simple analytical method based on solid-phase microextraction (SPME) followed by gas chromatography–flame photometric detection (GC–FPD) for the determination of eleven organophosphorus pesticide residues (i.e., ethoprophos, sulfotep, diazinon, tolclofos-methyl, fenitrothion, chlorpyrifos, isofenphos, methidathion, ethion, triazophos, leptophos) in vegetables samples (cabbage, kale and mustard) was developed. Important parameters that influence the extraction efficiency (i.e., fibre type, extraction modes, extraction time, salt addition, desorption time and temperature) were systematically investigated. Four types of commercially available fibres (i.e., 50/30μm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), 65μm polydimethylsiloxane/divinylbenzene (PDMS/DVB), 100μm polydimethylsiloxane (PDMS), and 85μm polyacrylate (PA)) were evaluated. PA fibre exhibited the best performance and was used for the rest of the studies. The optimised extraction conditions were: extraction time, 30min at room temperature; stirring speed, 1275rpm; salt content, 10% NaCl; desorption time and temperature, 11min at 260°C; and no pH adjustment of the sample extract. The method was validated over the range 0.1–100μg/L. Repeatabilities were satisfactory, ranging between 2.44% and 17.9% for all analytes. The limits of detection and quantitation ranged from 0.01 to 0.14 and 0.03 to 0.42μg/L, respectively. The method was applied to twenty local vegetable (cabbage, kale and mustard) products. Chlorpyrifos (0.22–1.68μg/kg) was the most detected pesticide in the tested samples. The obtained values are however lower than the Maximum Residue Limits (MRLs) as stipulated in the Food Act & Regulations of Malaysia

1 August 2017 in Journal of Chromatography A
Verified
Journal Article
Closed access
NSNor Shifa Shuib
Nor Shifa Shuib
AMAhmad Makahleh
Ahmad Makahleh
SSSalizawati Muhamad Salhimi
Salizawati Muhamad Salhimi
BSBahruddin Saad
Bahruddin Saad


1 July 2011 in Journal of Chromatography A
Verified
Journal Article
Closed access
CBChanbasha Basheer
Chanbasha Basheer
WWWeishan Wong
Weishan Wong
AMAhmad Makahleh
Ahmad Makahleh
ATAbdassalam Abdelhafiz Tameem
Abdassalam Abdelhafiz Tameem
ASAbdussalam Salhin
Abdussalam Salhin
HLHian Kee Lee
Hian Kee Lee

1 September 2012 in Analytica Chimica Acta
Verified
Journal Article
Closed access
NBNur Bahiyah Abu Bakar
Nur Bahiyah Abu Bakar
AMAhmad Makahleh
Ahmad Makahleh
BSBahruddin Saad
Bahruddin Saad