PMID- 33621935
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20210323
LR  - 20210323
IS  - 1873-3557 (Electronic)
IS  - 1386-1425 (Linking)
VI  - 253
DP  - 2021 May 15
TI  - Efficiency enhancement of the spectrophotometric estimation of cobalt in waters 
      and pharmaceutical preparations using dispersive liquid-liquid microextraction 
      and microcells with long optical paths.
PG  - 119552
LID - S1386-1425(21)00128-1 [pii]
LID - 10.1016/j.saa.2021.119552 [doi]
AB  - In this paper, dispersive liquid-liquid microextraction (DLLME), long optical 
      path microcells, and a selective chromogenic reagent were employed to improve the 
      analytical efficiency of cobalt determination by spectrophotometry. The 
      methodology proposed in the present study is based upon the microextraction of a 
      cobalt(II) complex with 1-[4-[(2-hydroxynaphthalen-1-yl)methylideneamino] 
      phenyl]ethanone (HNE) by DLLME and measurement of the absorbance of the 
      sedimented phase using a microcell with an optical path length of 50 mm 
      (Microcell-50). DLLME was performed using a binary mixture containing 900 muL of 
      methanol as a dispersing solvent and 400 muL of CHCl(3) (extraction solvent) at pH 
      6-8 adjusted by a mixture of HCl and NaOH. The electronic spectrum of the dark 
      brown complex recorded in the sedimented phase using Microcell-50 shows a 
      well-defined peak at lambda(max) 324 +/- 3 nm with a molar absorptivity of 1.08 x 10(6) 
      M(-1) cm(-1). Cobalt was monitored at a detection limit (LOD) of 0.08 mug L(-1) 
      and in the linear concentration range of 0.45-10 mug L(-1), while the limit of 
      quantitation (LOQ), relative standard deviation (RSD), and the enhancement factor 
      (EF) were 0.264, 1.6 mugL(-1), and 223, respectively. Our method was evaluated by 
      determining cobalt in certified reference materials and experimental samples, and 
      the results were compared with ICP-MS measurements. Moreover, the chemical 
      structure of the [Co(C(38)H(28)O(2)N)(2)] complex was suggested through using 
      different characterization techniques such as Fourier transform infrared 
      spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray 
      spectroscopy (EDX), thermal analysis, and powder X-ray diffraction.
CI  - Copyright (c) 2021 Elsevier B.V. All rights reserved.
FAU - Al-Saidi, Hamed M
AU  - Al-Saidi HM
AD  - Department of Chemistry, University College in Al - Jamoum, Umm Al-Qura 
      University, 21955 Makkah, Saudi Arabia. Electronic address: hmsaidi@uqu.edu.sa.
FAU - Alharthi, Salman S
AU  - Alharthi SS
AD  - Department of Chemistry, College of Science, Taif University, P.O. Box 11099, 
      Taif 21944, Saudi Arabia.
LA  - eng
PT  - Journal Article
DEP - 20210205
PL  - England
TA  - Spectrochim Acta A Mol Biomol Spectrosc
JT  - Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy
JID - 9602533
SB  - IM
OTO - NOTNLM
OT  - Characterization
OT  - Cobalt
OT  - Determination
OT  - Microcell
OT  - Spectrophotometry
COIS- Declaration of Competing Interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2021/02/24 06:00
MHDA- 2021/02/24 06:01
CRDT- 2021/02/23 20:14
PHST- 2020/10/13 00:00 [received]
PHST- 2021/01/09 00:00 [revised]
PHST- 2021/01/26 00:00 [accepted]
PHST- 2021/02/24 06:00 [pubmed]
PHST- 2021/02/24 06:01 [medline]
PHST- 2021/02/23 20:14 [entrez]
AID - S1386-1425(21)00128-1 [pii]
AID - 10.1016/j.saa.2021.119552 [doi]
PST - ppublish
SO  - Spectrochim Acta A Mol Biomol Spectrosc. 2021 May 15;253:119552. doi: 
      10.1016/j.saa.2021.119552. Epub 2021 Feb 5.