Continuous chemiluminescence determination of formaldehyde in air based on Trautz-Schorigin reaction

A new continuous method for the determination of formaldehyde in air is described. A cylindrical wet effluent diffusion denuder is used for the collection of formaldehyde from air into a thin film of absorption liquid (distilled-deionized water). Formaldehyde in the denuder concentrate is on-line detected employing a chemiluminescence flow method based on a reaction of formaldehyde and gallic acid with hydrogen peroxide in an alkaline solution. The collection efficiency of formaldehyde is quantitative at the air flow rate of 0.5 L min⁻¹ (absorption liquid flow rate of 336 μL min⁻¹). The limit of detection (S/N = 3) is 0.60 μg m⁻³ HCHO (0.49 ppb). The calibration graph is linear up to 300 μg m⁻³ HCHO (244 ppb). The relative standard deviations of chemiluminescence method for 1 × 10⁻⁶ and 5 × 10⁻⁶ M HCHO are 2.87% and 1.49%, respectively. Acetaldehyde interferes negligible, other compounds do not interfere. The method was employed for formaldehyde measurement in ambient air. The comparison measurement illustrates the good agreement of results obtained by proposed method with those obtained by reference fluorimetric method.     

纳米银催化的鲁米诺化学发光体系测定呋喃硫胺的研究

基于纳米银能够增强鲁米诺-H2O2-呋喃硫胺体系化学发光的现象,建立了测定呋喃硫胺的流动注射化学发光新方法.对体系的化学发光机理进行了初步探讨,发现该体系的化学发光光谱的最大发射波长为425nm,该体系的发光体为激发态的3-氨基邻苯二甲酸根离子.该方法测定呋喃硫胺的线性范围为1.0×10-8～1.0×10-5g/mL,检出限4×10-9g/mL,对1.0×10-6g/mL呋喃硫胺连续9次测定的相对标准偏差(RSD)为1.9％.方法已用于药物呋喃硫胺片中呋喃硫胺的测定.     

流动注射化学发光法检测甲醛含量的研究

甲醛能与氨基硫脲反应,从而抑制鲁米诺—氨基硫脲-Au(Ⅲ)体系的化学发光.在优化的条件下,甲醛加入量在0.2～15μg范围与发光强度呈良好的线性关系,方法的检测限为0.1 μg.方法可用于密胺餐具浸泡液中甲醛含量的检测.     

A study of the chemiluminescence behavior of myoglobin with luminol and its analytical applications

A chemiluminescence signal at 425 nm was observed when ferric state myoglobin was mixed with luminol in alkaline medium. Because the signal was remarkably enhanced in the presence of Fe(CN)₆ ^4–, analytical applications were investigated in a flow-injection system. The increase in chemiluminescence was linearly dependent on myoglobin concentration in the range 0.1 to 100 nmol L^–1, and the limit of detection was 0.04 nmol L^–1 with relative standard deviation 3.2% (3). It was also found that binding of Mb with the ligands CN^–, SCN^–, and F^– significantly inhibited the chemiluminescence reaction. The linear dynamic ranges for the ligands were 1.0–300.0, 0.1–3.0, and 0.5–100.0 nmol L^–1, and the limits of detection (S/N=3) 0.4, 0.04, and 0.2 nmol L^–1, for F^–, CN^–, and SCN^–, respectively. The relative standard deviations were 5.32%, 6.13%, and 3.38% for 0.1 nmol L^–1 CN^–, 0.5 nmol L^–1 SCN^–, and 1.0 nmol L^–1 F^–, respectively. At a flow rate of 2.0 mL min^–1 the assay could be accomplished in 1 min, including sampling and washing. The method has been successfully applied to the determination of myoglobin in human urine and F^– in water samples. A possible mechanism of chemiluminescence production by myoglobin and luminol is presented.     

Flow-injection chemiluminescence determination of formaldehyde in water

A modification of the Trautz-Schorigin reaction into a flow-injection analysis configuration is described. Different approaches were used at the optimization of chemiluminescence determination of formaldehyde in water based on the reaction of formaldehyde, gallic acid and hydrogen peroxide in an alkaline solution. Detection system with a 218 μl chemiluminescence cell was optimized by both a one-variable-at-a-time method, and a modified simplex method. A calibration graph is linear in the concentration range 4 × 10⁻⁸ to 1 × 10⁻⁵ M HCHO. The detection limit of formaldehyde for a signal-to-noise ratio of 3 is 4 × 10⁻⁸ M. The relative standard deviations for 15 repeated measurements of 1 × 10⁻⁶ and 5 × 10⁻⁶ mol l⁻¹ HCHO are 4.32 and 3.33%, respectively. The analysis time is 1.5 min. The method was applied to the determination of formaldehyde in urban rainwater. A comparison of results found by proposed method with those obtained by fluorimetric reference method provided a good agreement.     

Determination of thyroxine hormone by luminol chemiluminescence

A chemiluminescence (CL) flow system for determination of thyroxine (Thy) is presented. It is based on the catalytic effect of cobalt(II) on the CL reaction between luminol and hydrogen peroxide. The iodinated chemical structure of Thy causes a heavy atom effect. The luminol CL signals show significant quenching by Thy. The calibration graph for Thy is linear for 15-70 μg ml⁻¹ and the 3σ detection limits are 27 μg ml⁻¹ for d-Thy and 23 μg ml⁻¹ for l-Thy.     

流动注射阻抑化学发光法测定环境水中的酚

A new flow injection chemiluminesenet method was presented for the determination of phenol based on the inhibition effect of trace phenol on the chemiluminescence reaction between luminol and N-chlorosuccinimide system.The linear range for the determination of phenol is 1.5×10~(-5)~3.5×10~(-4)mg/mL,the detection limit is 2.36×10~(-6)mg/mL.This method has been used for the determination of phenol in water samples with satisfactory results.The mechanism of the inhibitory reaction was also discussed.     

Determination of trace amounts of formaldehyde in acetone

A method to quantify sub-ppm levels of formaldehyde in acetone has been developed and it is reported here. In this method, the different reactivities and stabilities of sulfite with formaldehyde and acetone are used to separate the two carbonyl compounds. Sulfite reacts with formaldehyde to form hydroxymethanesulfonate (HMS), the non-volatile and stable nature of which allows its separation from bulk acetone solvent. The resulting HMS is then converted back to formaldehyde under basic conditions, and formaldehyde is derivatized with 2,4-dinitrophenylhydrazine (DNPH) and quantified in its DNP hydrazone form using high-performance liquid chromatography-UV detection. The method detection limit at the 99% confidence level was 0.051 mg L⁻¹. A batch of samples can be processed within 4 h. The method has been applied to quantify the amount of formaldehyde in an analytical-grade acetone and in a commercial nail polish remover and the level of formaldehyde was found to be 0.175 and 0.184 mg L⁻¹, respectively.     

化学发光法测定痕量绿原酸

基于绿原酸对鲁米诺-H2O2-辣根过氧化物酶化学发光体系具有强烈的抑制作用,建立了绿原酸的化学发光分析法,并探讨了其作用机理。化学发光强度的变化值与绿原酸浓度的对数在5.2×10-9～1.0×10-6g/mL范围内呈线性关系,检出限(S/N=3)达7.8×10-10g/mL。该方法成功用于金银花中绿原酸含量的测定,回收率为96.0%～100.7%。     

Flow-injection chemiluminescence determination of aminomethylbenzoic acid and aminophylline based on N-bromosuccinimide-luminol reaction

A novel and sensitive chemiluminescence (CL) method for the determination of aminomethylbenzoic acid and aminophylline coupled with flow-injection analysis (FIA) technique is developed in this paper. It is based on the inhibition effect of the studied drugs on the chemiluminescence emission of N-bromosuccinimide-luminol (NBS-luminol) system. Under the optimum conditions, the decreased CL intensity is linear with the concentration of aminomethylbenzoic acid in the range of 2×10⁻⁸ to 1.0×10⁻⁶ g ml⁻¹ and with the concentration of aminophylline in the range of 1×10⁻⁷ to 7.0×10⁻⁶ g ml⁻¹, respectively. The detection limit is 7.0×10⁻⁹ g ml⁻¹ for aminomethylbenzoic acid (3σ) and 3.4×10⁻⁸ g ml⁻¹ for aminophylline (3σ). The relative standard deviations (R.S.D.) for 11 parallel measurements of 2.0×10⁻⁷ g ml⁻¹ aminomethylbenzoic acid and 1.0×10⁻⁶ g ml⁻¹ aminophylline are 2.6 and 3.0%, respectively. The proposed methods have been applied for the determination of the studied drugs in their pharmaceutical formulations with satisfactory results. The possible use of the proposed system for the determination of aminomethylbenzoic acid in plasma sample was also tested. The possible inhibition mechanism of aminomethylbenzoic acid and aminophylline on luminol-NBS system was discussed briefly.     

高锰酸钾-甲醛-扑尔敏体系化学发光的研究

在酸性介质中,KMnO4能氧化扑尔敏发生化学发光反应,甲醛的存在可使发光强度增强。据此,采用流动注射技术,建立了一种测定扑尔敏的化学发光分析法。方法的检出限为5×10-8g mL,相对标准偏差为0.7%(n=11,ρ=8×10-6g mL),线性范围为1.0×10-7～2.0×10-5g mL,该法已用于扑尔敏片剂中扑尔敏的测定。     

Determination of matrine in medicine and bio-fluids based on inhibition of luminol-myoglobin chemiluminescence

A green, rapid and sensitive flow injection procedure based on the inhibition of the chemiluminescence (CL) intensity from the luminol-myoglobin (Mb) system is proposed for the determination of matrine. The decrement of CL signal was linear with the logarithm of the matrine concentration over the range from 10 to 1000 ng/mL (R ² = 0.9978) offering a detection limit of 3.5 ng/mL. At a flow rate of 2.0 mL/min, one analysis cycle, including sampling and washing, could be accomplished in 0.5 min with a relative standard deviation (RSD) of less than 5.0%. The sensitive flow injection method was successfully applied to the determination of matrine in pharmaceutical injection and human serum, with recoveries from 94.1 to 113.4% and RSDs of less than 5.0%.     

流动注射-化学发光法测定非洛地平

基于非洛地平在碱性条件下对鲁米诺-K3Fe(CN)6化学发光体系具有很强的增敏作用,结合流动注射技术,建立了直接测定非洛地平的流动注射-化学发光新方法.方法的线性范围为6.0×10(-9)～3.0×10(-6)g/mL,检出限为2.1×10(-9)g/mL,对浓度为1.0×10(-7)g/mL非洛地平平行测定11次,其...     

An on-column fracture/end-column reaction interface for chemiluminescence detection in capillary electrophoresis

Chemiluminescence (CL) offers a sensitive detection method for capillary electrophoresis (CE), but the implementation of CE–CL is usually under compromised operating conditions for CE, such as the prerequisite of extreme pH buffer for optimal CL reaction at the capillary outlet. This has sometimes significantly deteriorated the separation of CE. In this study, the development of a new interface makes it possible to optimize the operating conditions for CE separation and CL detection independently. The interface consists of an on-column fracture being installed in a reservoir near the capillary end to create an electrical connection and also serve as reagent addition entrance. The capillary terminal is inserted into an end-column reservoir for CL reaction and detection. In this arrangement, the applied electric field has been decoupled from the CL detection, which is proved to effectively improve CE's performance by allowing the use of optimal CE buffers. At the same time, it enables the optimization of CL detection independently. The applicability of this interface was evaluated by using acridinium ester (AE) and luminol systems. For AE system, the interfering products of CL reagent (⁻OH, HO₂⁻) have been prevented, and the pH range of CE buffer can be independent to the optimal pH value of AE CL reaction, which is usually below 3. The AE was detected using running buffer at pH 8.7, giving a detection limit of 0.1 nM (S/N = 3), and the theoretical plate numbers is as high as 56 000. The on-column fracture based configuration is simple, sensitive and easy to implement.     

流动注射化学发光法测定盐酸美司坦

在碱性介质中,当把鲁米诺和KMnO4的混合溶液注入到盐酸美司坦溶液中时,会产生很强的化学发光现象。由此结合流动注射技术,建立了测定盐酸美司坦的流动注射化学发光新方法。该法的线性范围为2.0×10^-7-8.0×10^-6g/mL,检出限（3σ）为9×10^-8g/mL,对2.0×10^-6g/mL盐酸美司坦样品连续进行11次平行测定,其RSD为0.74%。已用于盐酸美司坦片剂中盐酸美司坦的测定。     

Enhancing and inhibiting effects of aromatic compounds on luminol-dimethylsulfoxide-OH(-) chemiluminescence and determination of intermediates in oxidative hair dyes by HPLC with chemiluminescence detection

The effect of 36 aromatic compounds on the luminol-dimethylsulfoxide-OH⁻ chemiluminescence (CL) was systematically studied. It was found that dihydroxybenzenes, and ortho- and para-substituted aminophenols and phenylenediamines inhibited the CL and phenols with three or more than three hydroxyls except phloroglucin tended to enhance the CL. The CL inhibition and enhancement was proposed to be dependent on whether superoxide anion radical (O₂⁻) was competitively consumed by compounds in the CL system. Trihydroxybenzenes were capable of generating superoxide anion radical, leading to the CL enhancement, whereas dihydroxybenzenes were superoxide anion radical scavenger, causing the CL inhibition. Based on the inhibited CL, a novel method for the simultaneous determination of p-phenylenediamine, o-phenylenediamine, p-aminophenol, o-aminophenol, resorcinol and hydroquinone by high-performance liquid chromatography coupled with chemiluminescence detection was developed. The method has been successfully applied to determine intermediates in oxidative hair dyes and wastewater of shampooing after hair dyed.     

流动注射化学发光测定水杨酸

基于在甲醛存在下 ,水杨酸与KMnO4在酸性介质中直接化学发光反应 ,建立了测定水杨酸的流动注射化学发光的方法 ,该法测定水杨酸的线性范围为5 .0× 1 0 -7～ 1 .0× 1 0 -3 mol L ,检出限为 3.0× 1 0 -7mol L ,相对标准偏差为 2 0 %(水杨酸 5 .0× 1 0 -5mol L ,n =1 1 )。该法已应用于脚癣药水中水杨酸的测定。     

Biomimetic enhanced chemiluminescence of luminol-H2O2 system by manganese (III) deuteroporphyrin and its application in flow injection determination of phenol at trace level

A novel, sensitive and high selective flow-injection chemiluminescence (FI-CL) method for the determination of phenol is reported, based upon its decreasing effect on the CL reaction of luminol with hydrogen peroxide catalyzed by manganese (III) deuteroporphyrin [MnDP, Scheme 1, 3] in alkaline solution. Under the selected optimized experimental conditions, the relative CL intensity was linear with phenol in the range of 4.0 × 10⁻⁹ to 4.0 × 10⁻⁷ g mL⁻¹. The detection limit (3σ) was 6.3 × 10⁻¹⁰ g mL⁻¹ and the relative standard deviation for 1.0 × 10⁻⁷ g mL⁻¹ phenol (n = 11) was 2.99%. The regression equation was I = 120.79 + 1.14 × 1010c (R = 0.9936). This method has been applied to the determination of phenol in water with satisfactory results.     

Study on the chemiluminescence behavior of bovine serum albumin with luminol and its analytical application

In this paper, the luminescence behavior of bovine serum albumin (BSA) and luminol was first studied by flow injection chemiluminescence (CL). It was found that the hyperchromic effect of luminol in the presence of BSA led to the acceleration of the electrons transferring rate of excited 3-aminophthalate, which greatly enhanced the CL intensity of luminol/dissolved oxygen reaction. The increments of CL intensity were proportional to the concentrations of BSA with a linear range from 0.01 to 7 nmol L(-1). It was also found that azithromycin could inhibit the CL intensity of luminol/BSA reaction. The decrements of CL intensity were logarithm over the concentrations of azithromycin ranging from 0.1 to 700 ng mL(-1). At a flow rate of 2.0 mL min(-1), a complete analytical process, which included sampling and washing, could be performed within 30s with relative standard deviations of less than 3.1%. This proposed method was successfully applied in assaying azithromycin in pharmaceutical and human serum samples with recoveries from 91.0 to 104.3%. The possible luminescence mechanism of luminol/BSA/azithromycin reaction was discussed in detail by CL, UV and fluorescence methods.     

Determination of chromium(III) and total chromium using dual channels on glass chip with chemiluminescence detection

A simple, rapid and sensitive method for the determination of chromium(III) and total chromium using the simple dual T channels on glass chip with negative pressure pumping system and chemiluminescence (CL) detection is presented. The CL reaction was based on luminol oxidation by hydrogen peroxide in basic aqueous solution catalyzed by chromium(III). Total chromium in form of chromium(III) was achieved after chromium(VI) was completely reduced by acidic sodium hydrogen sulfite. Total chromium could then be determined with the same strategy as the chromium(III). The CL reagent was composed of 1.0 × 10⁻⁴ mol/L luminol, 1.0 × 10⁻² mol/L hydrogen peroxide and 0.10 mol/L sodium bromide in 0.050 mol/L carbonate buffer (pH 11.00). The 1.0 × 10⁻² mol/L ethylenediaminetetraacetic acid was added into the sample solution in order to improve the selectivity. Chromium(III) could be detected at a notably concentration of 1.6 × 10⁻¹⁶ mol/L and a linear calibration curve was obtained from 1.0 × 10⁻¹⁵ to 1.0 × 10⁻¹³ mol/L. The sample and CL reagent consumption were only 15 and 20 μL, respectively. The analysis time was less than 1 min per sample with the precision (%R.S.D.) was 4.7%. The proposed method has been applied successfully to the analysis of river water, mineral waters, drinking waters and tap water. Its performance was verified by the analysis of certified total chromium-reference materials and by recovery measurement on spiked synthetic seawater sample.