PMID- 21530978
OWN - NLM
STAT- MEDLINE
DCOM- 20110829
LR  - 20131121
IS  - 1873-3778 (Electronic)
IS  - 0021-9673 (Linking)
VI  - 1218
IP  - 23
DP  - 2011 Jun 10
TI  - Effective indirect enrichment and determination of nitrite ion in water and 
      biological samples using ionic liquid-dispersive liquid-liquid microextraction 
      combined with high-performance liquid chromatography.
PG  - 3595-600
LID - 10.1016/j.chroma.2011.04.014 [doi]
AB  - An ionic liquid dispersive liquid-liquid microextraction high-performance liquid 
      chromatography (IL-DLLME-HPLC) method for effective enrichment and determination 
      of nitrite ion in water and biological samples was developed. The method was 
      based on the reaction of nitrite ion with p-nitroaniline in the presence of 
      diphenylamine in acid media and IL-DLLME of azo product. The optimization of 
      reaction and extraction conditions, such as kind and concentration of acid, 
      reaction time, volume of reaction solvent, temperature, kind of extraction and 
      dispersive solvent, volume of extraction and dispersive solvent, addition of 
      salt, extraction and centrifugal time were studied. Under the optimal conditions, 
      1-octyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL-DLLME 
      procedure provided high enrichment factor of 430 and good extraction recovery of 
      91.7% for nitrite ion. The linearity was observed in the range of 0.4-500.0 mug 
      L(-)(1) with good correlation coefficient (r(2)=0.9996). The relative standard 
      deviations (RSDs) for five replicate measurements varied between 1.5% and 4.8%. 
      The limit of detection of the method (S/N=3) was 0.05 mug L(-)(1). The interference 
      effect of some anions and cations was also tested. The developed method allowed 
      achieving an excellent enrichment factor, yielding a lower LOD in comparison with 
      other methods. Moreover, the proposed method was able to analyze nitrite ion in 
      water and biological samples with satisfactory recovery ranged from 96.5% to 
      107.3%.
CI  - Copyright (c) 2011 Elsevier B.V. All rights reserved.
FAU - He, Lijun
AU  - He L
AD  - School of Chemistry and Chemical Engineering, Henan University of Technology, 
      Lianhua Street, Zhengzhou 450001, China. ljhe01@yahoo.com.cn
FAU - Zhang, Kaige
AU  - Zhang K
FAU - Wang, Caijuan
AU  - Wang C
FAU - Luo, Xianli
AU  - Luo X
FAU - Zhang, Shusheng
AU  - Zhang S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20110414
PL  - Netherlands
TA  - J Chromatogr A
JT  - Journal of chromatography. A
JID - 9318488
RN  - 0 (Ionic Liquids)
RN  - 0 (Nitrites)
RN  - 0 (Water Pollutants, Chemical)
RN  - 059QF0KO0R (Water)
RN  - Y4S76JWI15 (Methanol)
SB  - IM
MH  - Adult
MH  - Chemical Fractionation/*methods
MH  - Chromatography, High Pressure Liquid/*methods
MH  - Female
MH  - Humans
MH  - Ionic Liquids/chemistry
MH  - Methanol
MH  - Nitrites/*analysis/isolation & purification
MH  - Reproducibility of Results
MH  - Rivers/chemistry
MH  - Saliva/*chemistry
MH  - Sensitivity and Specificity
MH  - Water/*chemistry
MH  - Water Pollutants, Chemical/analysis
MH  - Water Supply
EDAT- 2011/05/03 06:00
MHDA- 2011/08/30 06:00
CRDT- 2011/05/03 06:00
PHST- 2010/12/30 00:00 [received]
PHST- 2011/04/02 00:00 [revised]
PHST- 2011/04/06 00:00 [accepted]
PHST- 2011/05/03 06:00 [entrez]
PHST- 2011/05/03 06:00 [pubmed]
PHST- 2011/08/30 06:00 [medline]
AID - S0021-9673(11)00482-1 [pii]
AID - 10.1016/j.chroma.2011.04.014 [doi]
PST - ppublish
SO  - J Chromatogr A. 2011 Jun 10;1218(23):3595-600. doi: 10.1016/j.chroma.2011.04.014. 
      Epub 2011 Apr 14.