The Determination of Iodide Based on a Flow-injection Coupling Irreversible Biamperometry

A novel flow-injection irreversible biamperometric method is described for the direct determination of iodide. The method is based on electrochemical oxidation of iodide at the gold electrode and the reduction of permanganate at the platinum electrode to form an irreversible biamperometric detection system. Under the applied potential difference of 0 V, in the 0.05 molL sulfuric acid, iodide can be determined over the range 4.00×10-7-1.00×10-5 molL with a sampling frequency of 120 samples per hour. The detection limit for I- is 3.0×107 molL and the RSD for 40 replicate determinations of 4.0×105 molL potassium iodide is 1.68%. The new method was applied to the analysis of iodide in table salt with satisfactory results.

Using Nuclear Magnetic Resonance and MS/MS Spectroscopy for the Identification of Brodimoprim Metabolites in Rat Urine

Eight metabolites of brodimoprim (BDP) in rat urine were detected by NMR and ESI-MS/MS. They were demethyl-BDP glucuronide, demethyl-BDP sulfurate, demethyl-BDP glucuronide sulfurate, (-hydroxyl-BDP, (-hydroxyl-BDP glucuronide, BDP sulfurate, N-oxide-BDP sulfurate, and (-hydroxyl-N-oxide-BDP sulfurate. All the sulfurates are reported for the first time.

Determination of chlorogenic acid by flow injection irreversible biamperometry

A flow injection irreversible biamperometric method for the determination of chlorogenic acid is described.The proposedmethod is based on the electrochemical oxidation of chlorogenic acid at pretreated platinum electrode and the reduction ofpermanganate at another electrode to form an irreversible biamperometric detection system.Under the external potential difference(△E)of 0 V,in the 0.05 mol/L sulfuric acid,chlorogenic acid can be determined over the range 0.8-120 mg/L with a samplemeasurement frequency of 80 samples/h.The detection limit is 0.18 mg/L.The proposed method exhibits the satisfactoryreproducibility with a relative standard derivation(R.S.D.)of 2.21%for 19 successive determinations of 40 mg/L.

Determination of levodopa in pharmaceutical preparations by irreversible biamperometry

在铂电极在金电极和高锰酸盐的减小基于 levodopa 的 electrocatalytic 氧化，新奇流动注射不可逆的 biamperometric 方法在在二个电极之间强加的 0 V 的潜在的差别下面为 levodopa 的决心被开发。在 H2SO4 答案，在水流和 levodopa 的集中之间的线性关系与 0.012 mg/L 的察觉限制从 0.04 mg/L 在范围被获得到 20 mg/L。建议方法在药品的准备被用于 levodopa 的决心。

Determination of ephedrine and codeine in human urine by cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography

为在由毛状的电气泳动(CE ) 的人的尿的麻黄素和 codeine 的决心的一个敏感方法被描述。为了改进敏感，包括阳离子选择的彻底的注射(CSEI ) 的二种联机集中技术和大规模 micellar 电镀物品，运动层析(sweeping-MEKC ) 被使用。在最佳条件下面，察觉限制(S/N = 3 ) 是 0.10 &#x3bc；为麻黄素和 0.80 &#x3bc 的 g/L；为 codeine 的 g/L。这个方法成功地被用于真实的尿样品分析。

Discrimination of Structural Isomers of Aromatic Compounds with EI Mass Spectra and Their Ionization Efficiency Curves of Dehydrogenated Fragment Ions

The mechanism of ionization and fragmentation for terphenyl (diphenylbenzene) withthree structural ring isomers (ortho-, meta- and para-), and stilbene (1,2-diphenylethylene) with two geometrical isomers (trans- and ets-) by EI mass spectrometry and ionizstion efficiency curves are investigation.