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  1. Nurul Izzaty Hassan, Musa Ahmad
    Sains Malaysiana, 2007;36:189-194.
    Analisis kuantitatif untuk penentuan kepekatan ion Al3+ dalam larutan akueus telah dilakukan menggunakan reagen alizarin red S (ARS) melalui pembentukan kompleks ARS-Al(III) yang dianalisis menggunakan kaedah spektrofotometri UL-Nampak. Kompleks ARS-Al(III) memberikan puncak serapan pada panjang gelombang 484 nm pada pH 5. Kajian kestabilan foto bagi reagen ARS memberikan nilai RSD sebanyak 0.46 %. Analisis kebolehulangan memberikan nilai RSD sebanyak 1.07 % dan 0.67 % masing-masingnya bagi kepekatan Al(III) 0.2 ppm dan 9 ppm. Gangguan kation Cu2+ dan Fe3+ pada nisbah mol 1:10 adalah minimum. Kebanyakan anion penggangu tidak memberikan kesan gangguan kecuali F- pada nisbah mol 1:1 dan 1:10. Sistem ini memberikan julat kepekatan dinamik Al3+ antara 0.1 – 1.0 ppm. Arkitektur ANN dengan bilangan neuron terlindung, bilangan kitaran dan kadar pembelajaran adalah masing-masingnya 23, 40000 dan 0.001 telah berjaya memanjangkan julat dinamik kepekatan Al(III) daripada 0.1 – 8.0 ppm. Reagen ARS berjaya dipegunkan pada permukaan ko-polimer XAD 4 dan mampu memberikan respon optik yang baik terhadap ion Al3+.
  2. Wong Sheryn, Jalifah Latip, Nurul Izzaty Hassan, Siti Aishah Hasbullah
    Sains Malaysiana, 2018;47:755-762.
    An efficient and a green route to synthesize phthalide-fused indoline, 3-[(5-chloro-1,3,3-trimethylindolin-2-ylidene)methyl]
    isobenzofuran-1(3H)-one (3) has been developed by the coupling reaction of 5-chloro-2-methylene-1,3,3-trimethylindoline,
    1 and 2-formylbenzoic acid, 2 under solvent-free domestic microwave irradiation. The compound was produced in 85%
    yield. Compound 3 was characterized by analytical and spectral methods and its structure was confirmed by chemical
    crystallography. Compound 3 was successfully crystallized in triclinic system with space group Pī. The molecular structure
    consists of fused 1 and 2 groups connected by the enamine carbon. Binding study of 3 towards different types of metal
    cations was done by colorimetric detection and UV-vis titrations. Compound 3 exhibited good selectivity and sensitivity
    for Sn2+ compared to other metal cations tested. The stoichiometric binding ratio of 3 toward Sn2+ is found to be 1:1
    and the binding constant (Ka) is 1.07×104 M–1 on the basis of Job’s plot and Benesi-Hildebrand analysis.
  3. Kook Shih Ying, Lee Yook Heng, Nurul Izzaty Hassan, Siti Aishah Hasbullah
    Sains Malaysiana, 2018;47:2657-2666.
    A copper ion sensor based on a new bis-thiourea compound N1
    ,N3
    -bis[[3,5-bis(trifluoromethyl)phenyl]carbamothioyl]
    isophthalamide (or TPC) as neutral carrier was investigated. The immobilization of the TPC into poly(n-butyl acrylate)
    (pBA) membrane via drop casting and the sensor was characterized by potentiometry. The sensor fabricated from TPC
    only showed a good Nernstian response towards copper ion with a sensitivity slope of 28.81±0.53mV/decade in the range
    of 1.0 × 10-6 - 1.0 × 10-4 M. The limit of detection of this sensor was found to be 6.11 × 10-7 M and with short sensor
    response time (60 - 80 s). This sensor also demonstrated reversibility and reproducibility with 3.69% and 1.84% (Relative
    Standard Deviation, RSD), respectively. Based on the separate solution method (SSM), the logarithm selectivity coefficients
    were better than -2.00 for monovalent, divalent and trivalent cations and this confirmed that the sensor exhibited good
    selectivity towards copper ion. The sensor could attain optimum function without the need in the inclusion of either
    lipophilic anions as a membrane additive nor plasticizer as a membrane softener. Thus, these are the main advantages.
    The addition of lipophilic anions into the pBA membrane could cause the sensitivity and selectivity of the copper ion
    sensor based on ionophore TPC to deteriorate.
  4. Nurul Zawani Alias, Zaini Yusoff, Sharizal Hasan, Nurul Zawani Alias, Nurul Izzaty Hassan, Wan Yaacob Wan Ahmad
    Sains Malaysiana, 2018;47:347-352.
    Selenocompounds have been widely synthesized for their potential in pharmacology. Ebselen, a selenazole oxide, is a
    glutathione peroxidase mimic which is known to possess high antioxidant activity. Four derivatives of 3-(2-amino-1,3-
    selenazol-4-yl)-2H-chromen-2-ones were synthesized by reacting 3-(2-bromoacetyl)-chromen-2-one derivatives with
    selenourea through Hantzsch reaction using NaF as a catalyst in methanol-water (1:1) at room temperature. These
    reactions were completed in 30 min and purified using column chromatography eluted with n-hexane-ethyl acetate (7:3)
    to give 50-83% yields. All the compounds were successfully characterized using IR, 1H and 13C NMR as well as mass
    spectrometry. The synthesized compounds were tested with DPPH assay to determine the free radical scavenging activity
    and were compared to gallic and ascorbic acids as standard. Nonetheless, all compounds exhibited weak free radical
    scavenging activity with IC50 value ranging from 672.13 to 984.03 µM signifying that the derivatives may possess weak
    antioxidant activities.
  5. Nuur Haziqah Mohd Radzuan, Nawwar Hanun Abdul Malek, Nurul Izzaty Hassan, Muntaz Abu Bakar, Mohammad Fadzley Ngatiman, Tan Ke Xin, et al.
    Sains Malaysiana, 2018;47:2083-2090.
    Borylated porphyrin is one of building blocks in coupling reactions to obtain the multiporphyrin containing two,
    three or more subunits of porphyrins. In this study, one of borylated porphyrin derivatives, 5-(4,4,5,5 – tetramethyl
    – 1,3,2 – dioxoborolane) -10,20 – diphenylporphyrin (B-DPP) was synthesized through four steps of reactions. The
    building block of porphyrin, dipyrromethane was synthesized through a condensation reaction in the presence of
    trifluoroacetic acid as catalyst. Subsequently, A2
    B2 type of porphyrin was obtained by Lindsey condensation reaction
    followed by bromination reaction to produce porphyrin halide. Suzuki cross coupling reaction between porphyrin
    halide and pinacolborane with Pd (II) catalyst afforded 40% of borylayed porphyrin. The product was successfully
    characterized by using nuclear magnetic resonance spectroscopy (NMR) and UV-Visible spectroscopy (UV-Vis). This
    compound crystallized from a mixture of dichloromethane/methanol to give violet needle-like crystal. Crystallographic
    studies showed this compound crystallized in monoclinic system with space group of P21
    /c.
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