- Research article
- Open Access
Chemiluminescence determination of surfactant Triton X-100 in environmental water with luminol-hydrogen peroxide system
© Liu et al 2009
- Received: 06 May 2009
- Accepted: 01 July 2009
- Published: 01 July 2009
The rapid, simple determination of surfactants in environmental samples is essential because of the extensive use and its potential as contaminants. We describe a simple, rapid chemiluminescence method for the direct determination of the non-ionic surfactant Triton X-100 (polyethylene glycol tert-octylphenyl ether) in environmental water samples. The optimized experimental conditions were selected, and the mechanism of the Luminol-H2O2-Triton X-100 chemiluminesence system was also studied.
The novel chemiluminescence method for the determination of non-ionic surfactant Triton X-100 was based on the phenomenon that Triton X-100 greatly enhanced the CL signal of the luminol-H2O2 system. The alkaline medium of luminol and the pH value obviously affected the results. Luminol concentration and hydrogen peroxide concentration also affected the results. The optimal conditions were: Na2CO3 being the medium, pH value 12.5, luminol concentration 1.0 × 10-4 mol L-1, H2O2 concentration 0.4 mol L-1. The possible mechanism was studied and proposed.
Under the optimal conditions, the standard curve was drawn up and quotas were evaluated. The linear range was 2 × 10-4 g·mL-1-4 × 10-2 g·mL-1 (w/v), and the detection limit was 3.97 × 10-5 g·mL-1 Triton X-100 (w/v). The relative standard deviation was less than 4.73% for 2 × 10-2 g·mL-1 (w/v) Triton X-100 (n = 7). This method has been applied to the determination of Triton X-100 in environmental water samples. The desirable recovery ratio was between 96%–102% and the relative standard deviation was 2.5%–3.3%. The luminescence mechanism was also discussed in detail based on the fluorescence spectrum and the kinetic curve, and demonstrated that Triton X-100-luminol-H2O2 was a rapid reaction.
- Environmental Water Sample
- Luminol Concentration
- Tolerable Ratio
Surfactants are employed in a vast number of uses including domestic and industrial detergents, solubilization of membranes, and pharmaceutical and cosmetic formulations. Until recently, surfactants have drawn much research interest as enhancers in some special reactions [1, 2]. With these extensive uses (more than 15 million tonnes/year), their toxicity and negative effect on the self-purification capability of surface water, make these synthetic organic compounds one of the main environmental concerns. Therefore, a number of sensitive and high resolution techniques have been developed for the determination of low concentrations of cationic surfactants and anionic surfactants in different matrices, including gas and liquid chromatography [3–7], spectrophotometry [8–11], electrochemical methods [12, 13], capillary electrophoresis [14, 15] and sensors[16, 17]. Chromatographic techniques are the major methods in the analysis of surfactants due to the high efficiency and high sensitivity. However, the most important drawback for practical applications is their complication, and chromatographic techniques do not lend themselves to rapid analysis or to on-site studies. Moreover, there are few assays for the determination of non-ionic surfactants.
In recent years, extremely sensitive analytical techniques based on chemiluminescence (CL) and bioluminescence systems have received considerable attention. Simplicity of detection, low detection limits, large calibration ranges and short analysis times are some of the characteristics that make the methods attractive. Additionally, there are a few reports about using CL methods to analyze surfactants in environmental samples [18, 19].
TritonX-100 is a water-soluble, liquid, non-ionic surfactant that is recognized as the performance standard among similar products. It is an octylphenol ethoxylate with an average of nine to ten moles of ethylene oxide and is a 100-percent active product. It is widely used as a substrate for detergents and in textile and fiber manufacture because of its excellent detergency, excellent wetting ability and excellent grease and oil removal from hard surfaces. In addition, it is also used as an enhancer in some reactions [21–23]. However, the detection methods for Triton X-100 are limited [24, 25]. To our knowledge, up to now, CL determination of Triton X-100 has not been reported.
The aim of our study is to develop a simple, rapid and sensitive CL method for the determination of non-ionic surfactant Triton X-100. This method is based on the fact that Triton X-100 could enhance the CL emission arising from the reaction of luminol with hydrogen peroxide. It has been successfully used to determine Triton X-100 in environmental water samples. Moreover, the mechanism of the Luminol-H2O2-Triton X-100 chemiluminesence system was studied in detail.
Optimization of alkaline medium
Effect of pH of luminol
Effect of luminol concentration
As the chemiluminescence reagent, luminol concentration affected the CL intensity. The experimental results showed that the CL intensity increased from 1.0 × 10-5 mol·L-1 to 2.0 × 10-3 mol·L-1 and reached the maximum value at the luminol concentration of 1.0 × 10-4 mol·L-1. So 1.0 × 10-4 mol·L-1was chosen as the optimal luminol concentration for subsequent experiments.
Effect of hydrogen peroxide concentration
The effect of H2O2 concentration (0.05 mol·L-1-0.5 mol·L-1) on the CL intensity was examined. The best signal-to-noise ratio was achieved when the concentration of H2O2 was 0.4 mol·L-1. So 0.4 mol·L-1 was chosen as the optimal H2O2 concentration.
The analytical characteristics of the CL method
Under the optimum experimental conditions, CL response to Triton X-100 concentration was linear in the range of 2 × 10-4 g·mL-1-4 × 10-2 g·mL-1 (w/v). The detection limit was 3.97 × 10-5 g·mL-1 (w/v), calculated from the International Union of Pure and Applied Chemistry (IUPAC) recommendations (3σ). The regression equation was ΔI = 474303C-35.775 with a correlation coefficient of 0.9996. The relative standard deviations (RSD) for 7 injections with 2 × 10-2 g·mL-1 (w/v) Triton X-100 was 4.73%.
Several research works have confirmed that some metal ions (Fe2+, Co2+ and Cu2+) could catalyze and enhance the CL signals greatly in a luminol-H2O2 CL system [26, 27]. Therefore, it is necessary to examine the interference of some coexisting foreign inorganic ions and organic compounds on the luminol-H2O2-Triton X-100 system in order to evaluate the selectivity of the new method. The interference studies were conducted by analyzing a standard solution of 1.0 × 10-2 g·mL-1 TritonX-100 to which increasing amounts of foreign ions are added. The tolerated limit of each foreign species was taken as a relative error of ± 5%. The tolerable ratio for foreign species was 1-fold for PO43-, 0.1-fold for Na+, Cl-, 0.1-fold for K+, 1 × 10-4-fold for Pb2+, Cu2+, 1 × 10-9-fold for Ni2+, 1 × 10-10-fold for Co2+, 0.5-fold for glucose, starch, respectively. Moreover, three kinds of other surfactant CTMAB, SDBS and Tween-80, which may co-exist with the Triton X-100 in the water sample were investigated. The tolerable ratio was 5-fold for CTMAB and Tween-80, 2-fold for SDBS. It can be seen that severe interference was caused by Co2+ and Ni2+. Thus, 1.0 × 10-3 mol·L-1 of EDTA was added to the luminol solution to restrain the interference from metal ions. With the addition of EDTA, the tolerable ratio improved to 1 × 10-3-fold for Ni2+, 1 × 10-4-fold for Co2+. It demonstrated that EDTA had an obvious restraining effect on metal ions.
Determination and recovery of Triton X-100 in lake water samples
Triton X-100 residue
(n = 7)
Nanhu Lake water
5 × 10-3
4.8 × 10-3
Tangxun Lake water
5 × 10-3
5.1 × 10-3
Kinetic curve of the CL reaction
The CL reaction mechanism
The difference of CL signal in the presence and absence of Triton X-100 in luminol-H2O2 system
luminol-H2O2-Triton X-100 (0.05%)
luminol-H2O2-Triton X-100 (0.1%)
luminol-H2O2-Triton X-100 (0.2%)
luminol-H2O2-Triton X-100 (0.5%)
luminol-H2O2-Triton X-100 (1%)
luminol-H2O2-Triton X-100 (2%)
luminol-H2O2-Triton X-100 (4%)
luminol-H2O2-Triton X-100 (8%)
Based on the discussions above and combining this with the kinetic curve, the possible mechanism of the present reaction was proposed as follows: (1) Luminol was oxidized by hydrogen peroxide to produce excited state 3-aminophthalate anion; (2) There were micelles with the addition of Triton X-100, and the reaction environment was improved, luminol molecules permeated into and concentrated in micelles, the reaction was sensitized and the quantum yield of the CL reaction was improved and the CL intensity was enhanced; (3) The excited state 3-aminophthalate anion rebounded to the ground state, producing emission [28, 29].
From the above results, it was concluded that this method provides a simple technique for quantitative analysis of Triton X-100. The CL intensity was linear with Triton X-100 concentration in the range of 2 × 10-4 g·mL-1-4 × 10-2 g·mL-1 (w/v). The detection limit was 3.97 × 10-5 g·mL-1 (w/v). The desirable recovery ratio ensured the accurate detection of Triton X-100 in environmental water samples. The mechanism was also investigated in detail by fluorescence spectrum and kinetic curve analysis.
All chemicals were of analytical reagent grade and doubled distilled water was used throughout. Luminol and Triton X-100 were purchased from Sigma Corporation. The 0.01 mol·L-1 luminol stock solution was prepared by dissolving 0.1772 g luminol with 5 mL 1 mol·L-1 NaOH solution and doubled distilled water to 100 mL. The luminol solution was stable for at least 1 week when stored in the refrigerator at 4°C. Working standard solutions of luminol were freshly prepared from the stock solution by appropriate dilutions with 0.2 mol·L-1 Na2CO3 before use and pH adjusted to 12.5 with 1 mol·L-1 NaOH. A standard solution of Triton X-100 (8% w/v) was prepared by dissolving 8 g Triton X-100 with doubly distilled water to 100 mL. Working standard solutions of Triton X-100 were freshly prepared from the stock solution by appropriate dilutions.
The CL signal was measured with a static method by a BPCL ultra-weak luminescence analyzer (Institute of Biophysics, Chinese Academy of Science, Beijing, China). The CL intensity, amplified by a sensitive photomultiplier tube (PMT) operated at -400 V, was measured under the control of a computer. Fluorescence spectra were obtained with a RF-5301PC fluorescence spectrophotometer (Shimadzu, Japan).
The regent solutions were injected rapidly into the sample pool (each solution was 100 μL) and in turn the reaction door closed instantly so that the reaction was in the dark. At the same time, the computer program was started immediately to record the CL signal. The CL intensity ΔI was calculated by ΔI = Is-I0, where Is and I0 are the CL signals in the presence and absence of Triton X-100, respectively. All analysis was performed according to this procedure.
Kinetic curve method
100 μL Triton X-100 (1 × 10-2 g·mL-1), 100 μL H2O2 (0.4 mol·L-1) and 100 μL luminol (1.0 × 10-4 mol·L-1) were injected into the sample pool in the correct order. According to the analytical procedure, the CL signal was collected and recorded consecutively within 100 seconds. And then the curve of CL intensity-time (kinetic curve) was drawn up.
Water samples were picked from Nanhu Lake and Tangxun Lake near our campus and also near the countryside. Prior to analysis, the collected water was filtered using a standard 0.45 μm cellulose filter. In order to perform the recovery test, a known amount of Triton X-100 standard solution was added to the samples and then the mixture was diluted to suitable concentration with doubled distilled water for analysis.
This study was supported by the Tackle Key Project Foundation of Hubei Province of China (Grant No.2006AA201C40).
- Erbao L, Bingchun X: Flow injection determination of adenine at trace level based on luminol-K2Cr2O7 chemiluminescence in a micellar medium. J Pharm Biomed Anal. 2006, 41 (2): 649-653. 10.1016/j.jpba.2005.12.012.View ArticleGoogle Scholar
- Alan T, Napaporn YR, Alan W, Saisunee L: Flow-injection determination of cinnarizine using surfactant-enhanced permanganate chemiluminesence. Anal Chim Acta. 2003, 499 (1–2): 223-233.Google Scholar
- Qing Z, Justin S, Eric DC: Investigation of a variety of cationic surfactants attached to cation-exchange silica for hydrophobicity optimization in admicellar solid-phase extraction for high-performance liquid and gas chromatography. J Chromatogra A. 2006, 1132 (1–2): 1-7.Google Scholar
- Javier M, Antonio LZ, Else L: A high-performance liquid chromatography method for determination 2-(n-(N,N,N-trimethyl)-n-alkyl)-5-alkylfuryl halides in dipalmitoylphosphatidilcholine liposome solutions. J Chromatogr A. 2006, 1125 (1): 89-94. 10.1016/j.chroma.2006.05.031.View ArticleGoogle Scholar
- Manuel C, Soledad R, Dolores PB: Determination of non-ionic polyethoxylated surfactants in waste water and river water by mixed hemimicelle extraction and liquid chromatography-ion trap mass spectrometry. J Chromatogr A. 2005, 1067 (1–2): 161-170.Google Scholar
- Lanfang HL, Jay LG, Jodie VJ: Simultaneous quantification of poly-dispersed anionic, amphoteric and nonionic surfactants in simulated wastewater samples using C18 high-performance liquid chromatography-quadrupole ion-trap mass spectrometry. J Chromatogr A. 2005, 1062 (2): 217-225. 10.1016/j.chroma.2004.11.038.View ArticleGoogle Scholar
- Hong SP, Choong KR: Simultaneous determination of nonionic and anionic industrial surfactants by liquid chromatography combined with evaporative light-scattering detection. J Chromatogr A. 2004, 1046 (1–2): 289-291.Google Scholar
- March JG, Gual M, Frontera AD: A new reagent for a simple nephelometric determination of anionic surfactants. Anal Chim Acta. 2005, 539 (1–2): 305-310. 10.1016/j.aca.2005.03.020.View ArticleGoogle Scholar
- Eman MEN, Nahla MB, Saad SMH: Cobalt phthalocyanine as a novel molecular recognition reagent for batch and flow injection potentiometric and spectrophotometric determination of anionic surfactants. Talanta. 2009, 78 (3): 723-729. 10.1016/j.talanta.2008.12.029.View ArticleGoogle Scholar
- Yukio Y, Hidetaka K, Hisakuni S: Highly sensitive spectrophotometric determination of cationic. Talanta. 2008, 77 (2): 667-672. 10.1016/j.talanta.2008.07.021.View ArticleGoogle Scholar
- Shuting L, Shulin Z: Spectrophotometric determination of cationic surfactants with benzothiaxolyldiazoaminoazobenzene. Anal Chim Acta. 2004, 501 (1): 99-102. 10.1016/j.aca.2003.09.014.View ArticleGoogle Scholar
- M JS, Josefa LS, Juan S: Ion-selective electrodes for anionic surfactants using a new aza-oxa-cycloalkane as active ionophore. Anal Chim Acta. 2004, 525 (1): 83-90. 10.1016/j.aca.2004.07.032.View ArticleGoogle Scholar
- Craig JA, Mark MR: Measurement of fatty amine ethoxylate surfactants using electrochemiluminescence. Anal Chim Acta. 1999, 402: 105-112. 10.1016/S0003-2670(99)00535-8.View ArticleGoogle Scholar
- Nevin Öztekin, Bedia E: Determination of cationic surfactants as the preservatives in an oral solution and a cosmetic product by capillary electrophoresis. J Pharm Biomed Anal. 2005, 37 (5): 1121-1124. 10.1016/j.jpba.2004.07.050.View ArticleGoogle Scholar
- ShuPing W, Wen-Tsong L: Determination of benzophenones in a cosmetic matrix by supercritical fluid extraction and capillary electrophoresis. J Chromatogr A. 2003, 987 (1-2): 269-275. 10.1016/S0021-9673(02)01821-6.View ArticleGoogle Scholar
- Madunić-čaČić D, Sak-Bosnar M, Olivera G: Determination of cationic surfactants in pharmaceutical disinfectants using a new sensitive potentiometric sensor. Talanta. 2008, 76 (2): 259-264. 10.1016/j.talanta.2008.02.023.View ArticleGoogle Scholar
- Montserrat C, Christina E, Daniel C, Manuel V: Automated electronic tongue based on potentiometric sensors for the determination of a trinary anionic surfactant mixture. Journal of Pharmaceutical and Biomedical Analysis. 2008, 46 (2): 213-218. 10.1016/j.jpba.2007.09.013.View ArticleGoogle Scholar
- GuoFang Z, Hongyuan C: Studies of micelle and trace non-polar organic solvent on a new chemiluminescence system and its application to flow injection analysis. Anal Chim Acta. 2000, 409: 75-81. 10.1016/S0003-2670(99)00856-9.View ArticleGoogle Scholar
- Afsaneh S, Mohammad AK: Flow injection determination of cationic surfactants by using N-bromosuccinimide and N-chlorosuccinimide as new oxidizing agents for luminol chemiluminescence. Anal Chim Acta. 2002, 468: 53-63. 10.1016/S0003-2670(02)00592-5.View ArticleGoogle Scholar
- Haiyan G: Review of the application of non-ionic surfactants. Chin J Prac Tech. 1997, 24-25.Google Scholar
- Jason W, Karen JB, Mark MR: Enhanced electrochemiluminescence from Os(phen)2(dppene)2+ (phen=1,10-phenanthroline and dppene=bis(diphenylphosphino)ethene) in the presence of Triton X-100 (polyethylene glycol tert-octylphenyl ether). Analytica Chimica Acta. 2004, 503 (2): 241-245. 10.1016/j.aca.2003.10.029.View ArticleGoogle Scholar
- Changqing Z, Hong Z, Donghui L, Shunhua L, Jingou X: Fluorescence quenching method for the determination of sodium dodecyl sulphate with near-infrared hydrophobic dye in the presence of Triton X-100. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2004, 60 (13): 3173-3179. 10.1016/j.saa.2004.02.033.View ArticleGoogle Scholar
- Sarah AR, Alaílson FD, Helena VJ, Antônio CSC: Spectrofotometric determination of copper in sugar cane spirit using biquinoline in the presence of ethanol and Triton X-100. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2008, 71 (4): 1414-1418. 10.1016/j.saa.2008.04.013.View ArticleGoogle Scholar
- Göran K, Ann-Charlotte H, Elisabeth H, Stefan W: Determination of Triton X-100 in plasma-derived coagulation factor VIII and factor IX products by reversed-phase high-performance liquid chromatography. Journal of Chromatography A. 2002, 946 (1–2): 163-168.Google Scholar
- Ales S, Peter R, Horst S, Raimund S, Djuro J: Extraction of Triton X-100 and its determination in virus-inactivated human plasma by the solvent-detergent method. Journal of Chromatography A. 1994, 658 (2): 475-481. 10.1016/0021-9673(94)80038-3.View ArticleGoogle Scholar
- Denis B, Paolo P, Gabriella F, Carlo M: Effect of eluent composition and pH and chemiluminescent reagent pH on ion chromatographic selectivity and luminol-based chemiluminescence detection of Co2+, Mn2+ and Fe2+ at trace levels. Talanta. 2007, 72 (1): 249-255. 10.1016/j.talanta.2006.10.026.View ArticleGoogle Scholar
- Baoxin L, Dongmei W, Jiagen L, Zhujun Z: Flow-injection chemiluminescence simultaneous determination of cobalt(II) and copper(II) using partial least squares calibration. Talanta. 2006, 69 (1): 160-165. 10.1016/j.talanta.2005.09.017.View ArticleGoogle Scholar
- White EH, Bursey MM: Chemiluminescence of luminol and related hydrazides: the light emission step. J Am Chem Soc. 1964, 86: 940-942. 10.1021/ja01059a050.View ArticleGoogle Scholar
- Zhujun Z, Jiuru L, Xinrong Z: Luminol chemiluminescence reaction in analytical chemistry. Chin Chemical Reagents. 1987, 9 (3): 149-156.Google Scholar