Use of a Carbon Paste Electrode Modified with Spinel‐Type Manganese Oxide as a Potentiometric Sensor for Lithium Ions in Flow Injection Analysis

A potentiometric sensor constructed from a mixture of 25% (m/m) spinel‐type manganese oxide (lambda‐MnO₂), 50% (m/m) graphite powder and 25% (m/m) mineral oil is used for the determination of lithium ions in a flow injection analysis system. Experimental parameters, such as pH of the carrier solution, flow rate, injection sample volume, and selectivity for Li⁺ against other alkali and alkaline‐earth ions and the response time of this sensor were investigated. The sensor response to lithium ions was linear in the concentration range 8.6×10^?5–1.0×10^?2 mol L^?1 with a slope 78.9±0.3 mV dec^?1 over a wide pH range 7–10 (Tris buffer), without interference of other alkali and alkaline‐earth metals. For a flow rate of 5.0 mL min^?1 and a injection sample volume of 408.6 μL, the relative standard deviation for repeated injections of a 5.0×10^?4 mol L^?1 lithium ions was 0.3%.     

集成微管路离子选择电极功能块研究

本文对微型管状离子选择电极在流动条件下的电化学特征进行了研究,并设计了新的集成微管路离子选择以电极功能块。用此微型装置测定了土壤、血清、水和药物中的K~+、Na~+、pH、Cl~-、F~-、阿托品、东茛菪碱,并和各种标准方法作了比较,获得满意分析结果。     

反向流动注射化学发光法测定痕量铁

基于邻菲别名林对高碘酸钾－碱性鲁米诺－铁体系发光强度的增敏作用建立了水体中总铁的反向流动性化学发光检测方法。该法线性范围在１×１０＾－４－１０ｍｇ／Ｌ，检测限为３×１０＾－６ｍｇ／Ｌ，对于５×１０＾－３ｍｇ／Ｌ Ｆｅ测定９次的相对标准偏差为０．９％。此方法已用在水处理中总铁的监测。     

流动注射在线阴离子树脂预富集火焰原子吸收测定痕量铜

研究了以阴离子交换树脂作吸附剂的流动注射在线微柱预富集火焰原子吸收测定铜的新方法。在最佳条件下富集１５０ｓ，富集２３倍，检出限０．２μｇ／Ｌ，ＲＳＤ为１．６％，分析速度２０次／ｈ。天然水样中可能存在的离子不干扰铜的测定。所建立的方法已用于水样中痕量铜的测定。     

On-column injection onto capillary columns. Part 2: Study of sampling conditions; practical recommendations

During one year continuous use of on-column injection, the typical advantages described in our first report have fully been confirmed. In addition the analysis of large sample volumes has proved promising. Only minor modifications have been applied to the on-column injector device. Broad evidence has been gathered showing that full separation efficiency of the capillary columns after on-column injection is attained only when cold trapping or the solvent effect, as band shortening mechanisms, are working- While, under the conditions of on-column injection, cold trapping is less efficient than with other injection techniques, the opposite holds true for the solvent effect. Compared with splitless injection, the danger of excessive solvent condensation on the column is increased. A working rule is presented for establishing the optimal chromatographic conditions for handling large sample volumes while ensuring full separation efficiency yet avoiding harm to the column.     

钯的高选择性流动注射分析方法的研究

Pd(Ⅱ)与DBC-偶氮氯膦在硫酸介质中经加热发生络合显色反应,将此显色反应与流动注射分析技术结合,研究了影响该流动注射显色体系的各种因素,建立了钯的流动注射分析方法.用该方法可不经分离直接测定二次阳极泥和氯化渣中的钯.     

Flow injection chemiluminescence determination of polyhydroxy phenols using luminol-ferricyanide/ferrocyanide system

It was found that the weak chemiluminescence produced from the reaction of polyhydroxy phenols with luminol in alkaline solution could be strongly enhanced by ferricyanide and ferrocyanide. Based on this found, a new flow injection chemiluminescence method is proposed for the determination of four polyhydroxy phenols: pyrogallol, phlorglucinol, quinol and resorcinol. The detection limits of the method are 0.03 μg ml⁻¹ pyrogallol, 0.03 μg ml⁻¹ phlorglucinol, 0.04 μg ml⁻¹ quinol, and 0.02 μg ml⁻¹ resorcinol. The possible mechanism of CL reactions is also discussed briefly.     

Volatile phase profiling of mainstream smoke by glass capillary gas-chromatographic techniques

A heated injection system for a microprocessor-controlled GC has been developed for the (GC)² analysis of the volatile phase of whole smoke of a cigarette. Effects of injection port temperature and the presence of a Cambridge filter pad are demonstrated. Chromatograms are shown for smoke samples with and without a Cambridge Filter with the sample valve oven at 25°, 165° and 205°C. The use of a flame ionization and a nitrogen-phosphorous detector is illustrated.     

Mesoporous titanium dioxide as a novel solid-phase extraction material for flow injection micro-column preconcentration on-line coupled with ICP-OES determination of trace metals in environmental samples

Mesoporous titanium dioxide as a novel solid-phase extraction material for flow injection micro-column preconcentration on-line coupled with ICP-OES determination of trace metals (Co, Cd, Cr, Cu, Mn, Ni, V, Ce, Dy, Eu, La and Yb) in environmental samples was described. Possessing a high adsorption capacity towards the metal ions, mesoporous titanium dioxide has found to be of great potential as an adsorbent for the preconcentration of trace metal ions in samples with complicated matrix. The experimental parameters including pH, sample flow rate, volume, elution and interfering ions on the recovery of the target analytes were investigated, and the optimal experimental conditions were established. Under the optimized operating conditions, a preconcentration time of 90 s and elution time of 18 s with enrichment factor of 10 and sampling frequency of 20 h⁻¹ were obtained. The detection limits of this method for the target elements were between 0.03 and 0.36 μg L⁻¹, and the relative standard deviations (R.S.D.s) were found to be less than 6.0% (n =7, c =5 ng mL⁻¹). The proposed method was validated using a certified reference material, and has been successfully applied for the determination of the afore mentioned trace metals in natural water samples and coal fly ash with satisfactory results.     

Application of amperometric sol-gel biosensor to flow injection determination of glucose

A glucose biosensor with enzyme immobilised by sol–gel technology was constructed and evaluated. The glucose biosensor reported is based on encapsulated GOX within a sol–gel glass, prepared with 3-aminopropyltriethoxy silane, 2-(3,4-epoxycyclohexyl)-ethyltrimetoxy silane and HCl. A flow system incorporating the amperometric biosensor constructed was developed for the determination of glucose in the 1×10⁻⁴–5×10⁻³ mol l⁻¹ range with a precision of 1.5%. The results obtained for the analysis of electrolytic solution for iv administration and human serum samples showed good agreement between the proposed method and the reference procedure, with relative error <5%.