蔬菜中有机磷农药辛硫磷的化学发光分析研究

研究发现,在碱性介质中,无机盐氯化钠显著增强有机磷农药辛硫磷在鲁米诺-H2O2体系中的化学发光信号,据此建立了测定辛硫磷的化学发光新方法并探讨了该化学发光反应的可能机理.在鲁米诺分析液浓度为5×10-4 mol/L,H2O2溶液浓度为0.3 mol/L,NaCl浓度为4 mol/L,pH值为13的条件下,辛硫磷的浓度在1.0×10-5～1.0×10-3 g/L范围内与化学发光强度呈良好的线性关系;检出限为5.4×10-6 g/L;对浓度为5.0×10-4 g/L的辛硫磷进行11次平行测定,相对标准偏差为4.6%;添加3水平(0.01～1.0 mg/kg)的回收率为86%～106%.本方法用于蔬菜中辛硫磷残留量的测定,结果与气相色谱法基本一致.     

Ru(bipy)2+3-CO2-3-SO2-3-KClO3体系化学发光法测定空气中的二氧化硫

提出了Ru(bipy) 2+ 3-CO 2- 3-SO 2- 3-KClO 3体系化学发光法测定溶液中亚硫酸盐的方法.SO 2- 3浓度与化学发光强度在1.0×10-7～1.0×10-4 mol/L 范围内成正比,检出限为8.76×10-8 mol/L,对1.0×10-4 mol/L SO2-3溶液6次测定的相对标准偏差为2.9%.该法用三乙醇胺作为吸收液,成功地用于测定空气中二氧化硫的含量,结果满意.     

流动注射化学发光法测定盐酸多巴胺

实验发现铈(Ⅳ)氧化盐酸多巴胺能产生弱发光,而罗丹明6G(Rh6G)能大大增强此弱发光,由此建立了流动注射化学发光法测定盐酸多巴胺的新体系。该方法的线性范围为1.0×10-6~1.0×10-4mol/L,方法的检出限为4.0×10-7mol/L。对1.0×10-5mol/L的盐酸多巴胺进行11次平行测定,其相对标准偏差为1.2%。该法已应用于盐酸多巴胺注射液中盐酸多巴胺含量的测定,取得了满意的结果。     

鲁米诺-焦性没食子酸体系抑制化学发光法测定5-磺基水杨酸

基于碱性介质中5-磺基水杨酸对鲁米诺-焦性没食子酸体系化学发光的抑制作用,建立了流动注射化学发光测定5-磺基水杨酸的新方法.在最佳实验条件下,测定5-磺基水杨酸的线性范围为1.0×10-7～1.0×10-5mol/L,相关系数为0.9996(n=5),检出限为6.8×10-8mol/,L(n=11),对1.0×10-6...     

流动注射-化学发光法测定咖啡酸

基于在酸性条件下,咖啡酸能增强高锰酸钾-罗丹明6G体系的化学发光强度,提出了测定咖啡酸的流动注射-化学发光法。在优化的试验条件下,咖啡酸的发光强度的增加值与其浓度在1.0×10-6～1.0×10-4mol.L-1范围内呈线性关系,检出限(3S/N)为2.4×10-8mol.L-1。方法用于咖啡酸片中咖啡酸含量的测定,回收率在98.0%～104.3%之间,相对标准偏差(n=11)为3.0%。     

化学发光法测定氨磷汀研究

实验发现,铈(Ⅳ)可以氧化氨磷汀产生弱的发光,而罗丹明6G(Rh6G)能大大增强此发光,由此建立了一种化学发光法测定氨磷汀的新方法。该方法的线性范围为1.0×10-7~1.0×10-5mol/L,检出限为6.4×10-8mol/L。对1.0×10-6mol/L的氨磷汀进行11次平行测定的相对标准偏差为2.6%。该法用于氨磷汀注射液中氨磷汀含量的测定,获得满意结果。     

反相流动注射化学发光法测定黄芩苷

在碱性介质中,K3Fe(CN)6氧化鲁米诺产生化学发光,黄芩苷对该体系化学发光具有强烈的抑制作用。利用该化学发光的抑制体系,结合反相流动注射技术,建立了测定黄酮类药物黄芩苷含量的新方法。在优化的条件下,黄芩苷浓度在1.0×10-8～1.0×10-7和3.0×10-7～4.0×10-6mol/L范围内与化学发光抑制强度ΔI呈良好的线性关系,检出限为1.0×10-9mol/L,对3.0×10-7mol/L的黄芩苷进行平行测定10次,得相对标准偏差(RSD)为1.7%。该方法可应用于银黄口服液中黄芩提取物(黄芩苷计)的含量测定。     

流动注射化学发光法测定3种氟喹诺酮类药物

研究发现,氟喹诺酮类药物对可溶性Mn(-甲醛化学发光体系有强烈的增敏作用,结合流动注射技术,建立了3种氟喹诺酮类药物诺氟沙星、氧氟沙星和环丙沙星的流动注射化学发光新方法。在优化的实验条件下(2×10-4molMn(-3%甲醛-3mol/L磷酸),本方法测定诺氟沙星、氧氟沙星和环丙沙星的线性范围分别为1.0×10-7～1.0×10-5mol/L,1.0×10-7～1.0×10-5mol/L和3.0×10-7～5.0×10-5mol/L;检出限分别为3×10-8mol/L,3×10-8mol/L,1×10-7mol/L;相对标准偏差(5.0×10-6mol/L氟喹诺酮类药物,n=11)分别为2.6%,1.6%和2.8%。该方法已用于诺氟沙星胶囊中诺氟沙星的含量测定。     

流动注射后化学发光法测定Ca~(2+)

实验发现Ca2+在铁氰化钾-钙黄绿素化学发光反应体系中的后化学发光反应.优化了反应条件,建立了一种利用后化学发光反应测定Ca2+的流动注射化学发光分析法.方法的线性范围为1.0×10-6～1.0×10-4 g/mL,检出限为3.0×10-7 g/mL, 相对标准偏差为1.8%(2.0×10-5 g/mL Ca2+,n=11).此法已用于自来水中Ca2+含量的测定,结果与标准方法测定值一致.     

流动注射化学发光法测定废水中Mn(Ⅱ)

鲁米诺与K2S2O8在碱性介质中能产生稳定的化学发光信号,Mn2+对鲁米诺过硫酸钾体系的化学发光产生微弱的抑制作用,而Ag+能增强Mn2+对发光体系的抑制作用,据此建立测定了废水中微量Mn2+的流动注射化学发光分析方法。Mn2+的浓度在1.0×10-10～1.0×10-7mol/L范围内与相对发光强度(ΔI)呈良好的线性关系,检出限为1.0×10-12mol/L;对1.0×10-7mol/LMn2+进行11次平行测定,其相对标准偏差RSD为1.3%。方法已用于测定废水中Mn2+的含量。     

Chemiluminescence of hemoglobin and identification of related compounds with the hemoglobin chemiluminescence in plasma

A low level of chemiluminescence by hemoglobin (Hb) was detected in the reaction with H2O2 and hydrogen donors such as gallic acid and catechins. The photon intensity was affected by the ferric state of Hb (methemoglobin > oxyhemoglobin), and was roughly correlated with the radical-scavenging potential of catechins. We hypothesized the reversible activation reaction of Hb as the chemiluminescence mechanism of the H2O2/gallic acid/Hb system. It is indicated that the oxidized-Hb (Hb-OOH) formation was a chemiluminescence-rate-determining step and one-electron reduction by a hydrogen donor of the compound-I-type intermediate ([.XFeIV] = O) proved a chemiluminescence-specificity-determining step. Spectral analysis showed that the photon emission from the H2O2/gallic acid/Hb system was produced without singlet oxygen generation. The concentration dependence of photon intensity suggests a high consumption ratio of H2O2 leading to protection from H2O2 toxicity. Albumin was defined as a hydrogen donor by the isolation of chemiluminescent substance in plasma using this chemiluminescence system.     

A carbon quantum dots‐enhanced chemiluminescence method for the determination of gallic acid in food samples

In this work, we show that gallic acid can significantly inhibit the chemiluminescence (CL) intensity of carbon quantum dots (CQDs)‐enhanced K₃Fe(CN)₆–luminol system. Under optimum conditions, the decrease in the CL intensity is proportional to the concentration of gallic acid over the range 0.01–1.0 μM, and the detection limit is 1.0 nM. The relative standard deviation of repeated intraday and interday determinations of gallic acid was 1.2–4.2%. This method was successfully applied to the determination of gallic acid in food samples, with recoveries in the range 94.0–103.0%. A possible mechanism of CL is discussed.     

Chemiluminescence of Horseradish Peroxidase and Acetaldehyde Related with Gallic Acid and Hydrogen Peroxide Interaction

Abstract— This study focuses on the fact that the chemiluminescence in the visible region is emitted from the H₂O₂/gallic acid/ horseradish peroxidase (HRP) and the H₂O₂/gallic acid acetaldehyde (MeCHO) systems. The concentration dependence of chemiluminescence intensity that led to the different response of HRP and MeCHO toward H₂O₂ indicates that the photon emission participates with peroxidase activity including an electron transfer reaction. From our experimental results, in this study, we postulated a reaction process for chemiluminescence based on a one-electron redox shuttle from H₂O₂ by peroxidase. The photon intensity and spectra data from the H₂O₂/ HRP and the H₂O₂/MeCHO systems with various cate-chins were not only affected by HRP and MeCHO but also corresponded with the chemical structure of cate-chins. The energy calculated from the spectra is 47–64 kcal/mol. These results suggested that the chemiluminescence of both systems arose from excited carbonyl compounds produced by an intermediate of the alkyl radical and the metal-bound hydroxyl (compound II species). Hydroxyl radical inhibition, showing a notable increase from the gallic acid addition, makes the decay of the hydroxyl form of heme iron the most likely candidate for the chemiluminescence.     

Determination of Gallic Acid by Flow Injection Analysis Based on Luminol‐AgNO3‐Ag NPs Chemiluminescence System

A novel flow injection procedure has been developed for the determination of gallic acid based on the enhancement function for luminol‐AgNO₃‐Ag NPs chemiluminescence (CL) system by gallic acid. The enhancement mechanism was proposed for the reinforcing effect of the gallic acid on the CL system. The UV‐vis absorption spectrum and CL emission spectrum were applied to confirm the mechanism. The method is simple, rapid and sensitive with a detection limit of 5×10^?10 g·mL^?1 and a linear range of 8.0×10^?10–1.0×10^?7 g·mL^?1. The relative standard deviation (RSD) is 1.3% for eleven measurements of 5×10^?8 g·mL^?1 gallic acid. The method has been successfully applied to the determination of gallic acid in Chinese proprietary medicine–Jianmin Yanhou tablets and synthesized samples.     

Application of direct-injection detector integrated with the multi-pumping flow system to chemiluminescence determination of the total polyphenol index

In this work, we present a novel chemiluminescence (CL) method based on direct-injection detector (DID) integrated with the multi-pumping flow system (MPFS) to chemiluminescence determination of the total polyphenol index. In this flow system, the sample and the reagents are injected directly into the cone-shaped detection cell placed in front of the photomultiplier window. Such construction of the detection chamber allows for fast measurement of the CL signal in stopped-flow conditions immediately after mixing the reagents. The proposed DID-CL-MPFS method is based on the chemiluminescence of nanocolloidal manganese(IV)-hexametaphosphate-ethanol system. The application of ethanol as a sensitizer, eliminated the use of carcinogenic formaldehyde. Under the optimized experimental conditions, the chemiluminescence intensities are proportional to the concentration of gallic acid in the range from 5 to 350 ng mL⁻¹. The DID-CL-MPFS method offers a number of advantages, including low limit of detection (0.80 ng mL⁻¹), high precision (RSD = 3.3%) and high sample throughput (144 samples h⁻¹) as well as low consumption of reagents, energy and low waste generation. The proposed method has been successfully applied to determine the total polyphenol index (expressed as gallic acid equivalent) in a variety of plant-derived food samples (wine, tea, coffee, fruit and vegetable juices, herbs, spices).     

Chemiluminescence change of polyphenol dendrimers with different core molecules

Second generation polyphenol dendrimers (PDs) with different core molecules were synthesized, and their chemiluminescence (CL) was measured by reacting the PDs with H2O2 under alkaline conditions. All of the PDs showed a strong CL, more than 120-fold greater than that of gallic acid. Various CL intensities of the PDs were obtained using different core molecules in the PDs. The distance between each dendron in the PD structure is crucial in the PD CL intensity.     

Improving continuous chemiluminescence determination method of formaldehyde in the atmosphere: reducing interference of acetaldehyde and others by using iodoform reaction

ABSTRACT

The continuous and selective determination method of formaldehyde (HCHO) in ambient air using chemiluminescence method has been developed. The counter current flow tube was used to collect gaseous formaldehyde. The major interferences of HCHO determination from acetaldehyde, ethanol, and ferrous ion were removed by applying iodoform reaction. Effect of acetaldehyde on chemiluminescence signal of formaldehyde at the same concentration was reduced from 19 to 0.3% by applying iodoform reaction. Subsequently, HCHO was online detected by measuring chemiluminescence produced from the reaction of HCHO, gallic acid, H₂O_2, and KOH. The limit of detection (S/N = 3) was 4.5 ppbv in air. The calibration graph was linear up to 6.25 ppmv. HCHO concentration measured by the present method showed good agreement with that obtained by the 2–4 DNPH-HPLC method.     

Flow injection chemiluminescence determination of the total phenolics levels in plant-derived beverages using soluble manganese(IV)

This study established a flow injection (FI) methodology for the determination of the total phenolic content in plant-derived beverages based on soluble manganese(IV) chemiluminescence (CL) detection. It was found that mixing polyphenols with acidic soluble manganese(IV) in the presence of formaldehyde evoked chemiluminescence. Based on this finding, a new FI-CL method was developed for the estimation of the total content of phenolic compounds (expressed as milligrams of gallic acid equivalent per litre of drink) in a variety of wine, tea and fruit juice samples. The proposed method is sensitive with a detection limit of 0.02 ng mL⁻¹ (gallic acid), offers a wide linear dynamic range (0.5-400 ng mL⁻¹) and high sample throughput (247 samples h⁻¹). The relative standard deviation for 15 measurements was 3.8% for 2 ng mL⁻¹ and 0.45% for 10 ng mL⁻¹ of gallic acid. Analysis of 36 different samples showed that the results obtained by the proposed FI-CL method correlate highly with those obtained by spectrophotometric methods commonly used for the evaluation of the total phenolic/antioxidant level. However, the FI-CL method was found to be far simpler, more rapid and selective, with almost no interference from non-phenolic components of the samples examined.     

流动注射—化学发光法测定苯甲醛

依据苯甲醛增强没食子酸－过氧化氢－氢氧化钠体系化学发光的性质，建立了苯甲醛的流动注射化学发光分析法。     

On-line column preconcentration for the determination of cobalt in sea water by flow-injection chemiluminescence detection

A flow-injection method for the determination of dissolved cobalt(II) in sea water has been studied based on a combination of column preconcentration using 8-quinolinol immobilized on silica gel, fluoride containing metal alkoxide glass (8HQ-MAF) and chemiluminescence detection with a gallic acid-hydrogen peroxide system. Co(II) is selectively recovered from an acidified sample with 8-quinolinol immobilized on silica gel. After elution with dilute hydrochloric acid the resultant eluent is mixed with the reagent solutions, heated to 60 ( degrees )C and then introduced into the CL cell. The analysis time including the 2-min sample load was 8 min per sea water sample with a corresponding detection limit of 0.62 ng l(-1) (3sigma). The average standard deviation calculated for 10 replicate measurements of artificial sea water samples with a concentration of 10 ng l(-1) cobalt was +/-2.1%. The method has been tested with the standard reference sea waters NASS and CASS.