Towards non-polluting organotin reagents for synthesis

New polymer-supported organotin reagents have been prepared. The reducing ability of a polystyrene-supported organotin hydride was evaluated by reaction with haloalkanes. The level of organotin pollution was monitored in comparison with that generated by Bu₃SnH, using ICP–MS analysis.     

酰氨基硫脲及其相关杂环衍生物的研究——Ⅱ.1-[5-(α-萘)-2 H-四唑-2-乙酰]-4-苯基氨基硫脲及其相关杂环衍生物的合成

本文合成了1-[5-(α-萘)-2 H-四唑-2-乙酰]-4-苯基氨基硫脲5,以及由5衍生的环化产物3-[5-(α-萘)-2 H-四唑-2-甲撑]-4-苯基-1,2,4-三唑啉-5-硫酮6,2-苯胺基-5-[5-(α-萘)-2 H-四唑-2-甲撑]-1,3,4-噻二唑7及2-苯胺基-5-[5-(α-萘)-2 H-四唑-2-甲撑]-1,3,4-(口恶)二唑8。它们的结构均通过元素分析,红外光谱,核磁共振及质谱鉴定。其药理实验正在进行中。初步实验表明,5及6对小麦生长有较强的促进作用。     

Validation of the determination of copper and zinc in blood plasma and urine by ICP MS with cross-flow and direct injection nebulization

The simultaneous determination of copper and zinc in human plasma and urine by inductively coupled plasma mass spectrometry (ICP MS) is discussed. The performances of a cross-flow nebulizer and a direct-injection nebulizer (DIN) were compared. Flow-injection-DIN-ICP MS analysis of clinical samples using 1-2 mul samples was optimized. Isobaric interferences were discussed and were demonstrated to be eliminated for the (65)Cu and most of the Zn nuclides. The need for standard addition to compensate for signal suppression in the case of some serum samples was indicated. Results obtained by ICP MS using calibration with aqueous standard solutions were found to be in good agreement with those obtained by flame AAS for a batch of real blood plasma and urine samples. The methods developed were validated by analysis of several standard reference materials.     

Aqueous ethylation of organotin compounds in simple solution for speciation analysis by cryofocussing and detection by atomic absorption spectrometry — comparison with hydride generation

A 2³ factorial experimental design has been used to determine the optimum reaction conditions for organotin ethylation in simple aqueous solutions for speciation by Cryogenic Trapping/ Gas Chromatography/Atomic Absorption Spectrometry (CT/GC/AAS). The factors chosen and their levels of variation (? and +) were the pH of the solution (levels 3 and 5), the amount of NaBEt₄ added (levels 1 and 9 mg) to the organotins and the time of ethylation reaction (levels 10 and 20 min). Optimum conditions were investigated for monomethyltin (MMT), diethyltin (DET) and dibutyltin (DBT) in mixed solution at a concentration of 10 ng of each Sn compound in 50 ml of solution (200 ng·l^?1). The influence of the different factors on the yield of the ethylation reaction in the ranges investigated depends on the degree of substitution and the nature of the alkyl groups of the organotins. The ethylation reaction for DET and DBT is more efficient at high pH levels, MMT gives higher yields at lower pH. Both MMT and DET require a high amount of reagent, while reagent concentration has no real influence on the DBT signal. Comparison of hydride generation and ethylation as derivatisation procedures for organotin speciation has been performed in simple solutions. Under these analytical conditions, hydride generation is shown to be slightly more sensitive than ethylation by a factor of 1.4 for MMT and DET and 2 for DBT. However derivatisation using ethylation provides more reproducible results and is not affected by inorganic interferents.     

流体静高压原位磁测量的误差研究（二）──退磁场的影响

 为了探讨流体静高压原位磁测量中退磁场的影响有多大？分别选用6种不同片数（n＝1、3、5、7、10、13）的非晶Fe_46.3Co_0.03Ni_46.5Si_3.75V_0.92B_2.5合金薄带样品，先后放进13层密绕直螺线管初级线圈内，采用工业频率400 Hz去测量和比较其磁化曲线、磁导率曲线和起始磁化曲线。研究表明：（1）样品片数越多，退磁场的影响越大，导致μ_m和μ_i出现惊人的测量误差，以1片（μ_m＝4 430，μ_i＝3 396）为最准。（2）随着样品片数的增多，测量饱和磁感应强度B_s＝0.837～0.762T，表明受退磁场影响较小。（3）若要减小退磁场误差，可将样品做得更薄，如0.2 μm薄膜。（4）若要彻底消除退磁场误差，必须采用闭合磁路，如用非晶合金薄带卷成的圆环。     

Organotin stability during storage of marine waters and sediments

Summary The stability of organotin compounds in water and sediment samples during storage and pre-treatment is of paramount importance. This study presents experiments with butyltin compounds showing that the storage of filtered natural seawater in the dark at pH 2 in pyrex glass bottles is suitable to preserve the stability of tributyltin (TBT) over 4 months both at 20–25°C and 4°C. The other butyltin compounds (mono- and dibutyltin) are stable at 4°C but display some losses at 25°C. A poor recovery of butyltins in turbid water hampered the assessment of the stability on a quantitative basis: however, it could be demonstrated on a qualitative basis that the butyltin stability is uneasily achieved in water samples with high suspended matter. Finally, wet storage and freezing are found to be suitable to preserve the tributyltin stability in sediments, as well as ovendrying (at 50°C), freeze-drying and air-drying. Mono- and dibutyltin are generally subject to changes during the storage of sediments using the different methods.     

Leaching of organotin compounds from poly(vinyl chloride) (PVC) material

The release of mono-and di-butyltin species (MBT and DBT) in water after leaching of five different poly(vinyl chloride) (PVC) materials was investigated under mild conditions over a period of one month in batch reactor systems. Results showed that inorganic tin, MBT and DBT compound were released from the material tested under experimental static leaching conditions. The total amount of inorganic tin and organotin compounds observed upon leaching varied considerably from one PVC material to another.