The anti-perovskite type hydride InPd3H0.89

Hydrogenation of tetragonal InPd₃ in the ZrAl₃ type structure (four-fold ccp superstructure) yields a hydride with a cubic AuCu₃ type structure (one-fold ccp superstructure). Deuterium can be located by neutron powder diffraction in octahedral voids surrounded exclusively by palladium, [Pd₆], which are 88.5(6)% occupied in a statistical manner. The resulting deuteride InPd₃D_0.89 thus crystallizes in a cubic anti-perovskite type structure (space group Pm3¯m (no. 221), a=402.25(1) pm at 299(2) K). The Pd-D distance of 201.13(1) pm is typical for interstitial hydrides with palladium. Inelastic neutron scattering on the hydride InPd₃H_0.89, which shows a spectrum similar to that of binary palladium hydride, confirms the cubic site symmetry of hydrogen in [Pd₆] interstices. This is also confirmed by the absence of any quadrupole splitting in the ²D-NMR signal of the deuteride. ¹H NMR spectra of InPd₃H_0.89 do not show any motional narrowing. Values found for the H jump rate τ⁻¹ in InPd₃H_0.89 remain below 10⁶ s⁻¹ in the studied temperature range 28-360 K, indicating a small hydrogen mobility in InPd₃H_0.8 as compared with binary palladium hydride, PdH_≤1. This can be attributed to the large spatial separation of the [Pd₆] sites.     

Simultaneous determination of Fe, P, Ca, Mg, Zn, and Cu in whole blood by two-jet plasma atomic emission spectrometry

Availability of many biological samples in ample quantity for biomedical investigations sometimes is very restricted. Therefore, there is the need for the simple techniques allowing the analysis of small amount samples. In the present work the two-jet plasma atomic emission spectrometry techniques for the determination of Fe, P, Ca, Mg, Zn, and Cu in whole blood are proposed. The first technique is developed for direct analysis of freeze-dried blood. The sample preparation consisted in a dilution of blood powder (particle size 20 μm or less) with a spectroscopic buffer (graphite powder containing 15 wt.% NaCl). For the analysis of liquid whole blood, previous carbonization (not ashing) of blood evaporated on graphite powder was applied. Calibration samples based on graphite powder containing 15 wt.% NaCl were used. The validation of the techniques was confirmed by the use of different sample preparation procedures (wet acid digestion and dry carbonization), the analysis of IAEA A-13 reference material (freeze-dried bovine whole blood), and the comparison of the results obtained by the proposed technique with the results of the stripping voltammetry technique. Just 20-50 μL of whole blood is quite enough for all determinations. The proposed techniques were successfully applied for the simultaneous determination of Fe, P, Ca, Mg, Zn, and Cu in whole blood of living experimental rats and mice and human blood.     

Recognition of active ingredients in tablets by chemometric processing of X-ray diffractometric data

The paper presents an approach to use Partial Least Squares Discriminant Analysis (PLS-DA) on X-ray powder diffractometry (XRPD) dataset to build a model which recognizes a presence (or absence) of particular drug substance (acetaminophen) in unknown mixture (OTC tablet). The dataset consisted of 33 XRPD signals, measured for 12 pure substances and 21 tablets containing them in different quantitative and qualitative ratios, along with unknown excipients. The model was built with an external validation dataset chosen by Kennard-Stone algorithm. The RMSECV value was equal to 0.3461 (87.8% of explained variance) and external predictive error (RMSEP) was equal to 0.3123 (86.2% of explained variance). The result suggests that small but properly prepared training datasets give ability to construct well-working discriminant models on XRPD signals.     

次氯酸钠对硫化橡胶粉表面的氧化改性研究

本文采用次氯酸钠对硫化橡胶粉进行表面氧化改性研究,通过X射线光电子能谱(XPS)、扫描电镜(SEM)、接触角测量对样品进行了表征和分析,并对其最佳工艺条件进行了探究。通过实验表明,氧化剂用量、反应温度及反应时间对胶粉的氧化反应都有影响。其最佳工艺条件的氧化剂用量为40%,反应温度为40℃左右,反应时间为3小时。     

超高效液相色谱-串联质谱联用法对奶粉中3种硝基咪唑残留物的测定

建立了超高效液相色谱-串联质谱联用法测定奶粉中甲硝唑(MNZ)、二甲硝唑(DMZ)和洛硝哒唑(RNZ)3种硝基咪唑类残留物的方法。样品以乙酸乙酯和乙腈提取,正己烷脱脂,浓缩过滤后进行超高效液相色谱-串联质谱分析,多反应监测正离子模式扫描。实验优化了质谱条件,并考察了方法的灵敏度、准确度、精密度和回收率。甲硝唑、二甲硝唑和洛硝哒唑的线性范围为2.5~100.0μg/L,定量下限均为2.5μg/kg,在2.5、5.0、10.0μg/kg 3个水平的加标回收率为89%~112%,相对标准偏差为4.0%~7.1%。该方法简捷、灵敏度高,可用于奶粉中硝基咪唑残留的检测。     

脉冲加热-热导法测定氮化锰粉末中的氮含量

介绍采用TC-600氧氮分析仪测定氮化锰粉末中氮的方法。对氮化锰粉末样品,采用手动模式进样。对加热功率、称样量、空白值等测定条件进行试验,确定了最佳测定条件。氮的加标回收率为98.18%~101.10%,测定结果的相对标准偏差小于1%(n=9)。该方法测定结果与化学法测定结果一致。     

Influence of the Electrode Material on the Electrochemical Behavior of Carbon Paste Electrodes Modified with Meldola Blue and Methylene Green Adsorbed on a Synthetic Zeolite

Carbon paste electrodes modified with a phenoxazine derivative, Meldola blue, and a phenothiazine derivative, methylene green, both strongly adsorbed on a synthetic zeolite were investigated using either glassy carbon powder (Sigradur K, SK) or single‐walled carbon nanotubes (SWCNT) as conductive electrode material. In the case of SWCNT based electrodes, the formal potential of both mediators was pH dependent, as expected for a redox process involving proton transfer. In contrast, the formal potential of both mediators of SK based modified electrodes was practically insensitive to pH. This behavior is discussed in terms of interactions existing in the heterogeneous system mediator‐zeolite‐electrode material.     

Quantitative analysis of perfumes in talcum powder by using headspace sorptive extraction

Quantitative analysis of perfume dosage in talcum powder has been a challenge due to interference of the matrix and has so far not been widely reported. In this study, headspace sorptive extraction (HSSE) was validated as a solventless sample preparation method for the extraction and enrichment of perfume raw materials from talcum powder. Sample enrichment is performed on a thick film of poly(dimethylsiloxane) (PDMS) coated onto a magnetic stir bar incorporated in a glass jacket. Sampling is done by placing the PDMS stir bar in the headspace vial by using a holder. The stir bar is then thermally desorbed online with capillary gas chromatography-mass spectrometry. The HSSE method is based on the same principles as headspace solid-phase microextraction (HS-SPME). Nevertheless, a relatively larger amount of extracting phase is coated on the stir bar as compared to SPME. Sample amount and extraction time were optimized in this study. The method has shown good repeatability (with relative standard deviation no higher than 12.5%) and excellent linearity with correlation coefficients above 0.99 for all analytes. The method was also successfully applied in the quantitative analysis of talcum powder spiked with perfume at different dosages.     

电感耦合等离子体原子发射光谱法(ICP-AES)测定无定形硼粉中的镁元素

提出了使用电感耦合等离子体原子发射光谱法(ICP-AES)测定无定形硼粉中Mg元素的分析方法。采用硝酸、盐酸溶解样品,用硝酸和盐酸的混合酸作为测定介质,在选定的仪器条件下直接测定。Mg元素的测定检出限为0.0044μg/mL,相对标准偏差(RSD,n=6)为0.49％～0.60％,样品加标回收率在94.0％～102.0％之间。经对比试验证明,本方法测定值与美国军用标准重量法测定值一致。     

新疆和田黑色透闪石质软玉振动光谱特征及颜色成因

采用X射线荧光光谱仪、X射线粉晶衍射仪、红外光谱仪、拉曼光谱仪等对黑色透闪石质软玉样品进行化学成分和谱学特征研究。通过X射线粉晶衍射判定所采样品全部属于透闪石质软玉,采用红外光谱仪和拉曼光谱仪对样品进行振动光谱测试,并结合化学成分测试结果分析墨玉的组成和颜色成因。结果显示,黑色透闪石质软玉可分为两种:由含铁量较高的阳起石组成的(TFe2O3:7.47Wt%～11.97 Wt%),另外一种是由透闪石和石墨组成,并且含铁量比较低(TFe2O3:0.56 Wt%～4.74 Wt%)。两者的振动光谱特征与透闪类矿物基本一致,在含石墨透闪石的拉曼光谱中出现了石墨特征峰1 581cm-1。因此,拉曼光谱在区分阳起石致色和石墨致色的黑色透闪石质软玉比红外光谱更加敏锐,该方法可以成为无损鉴定黑色透闪石质软玉颜色成因和产地来源的重要辅助手段。