多元光谱拟合-电感耦合等离子体原子发射光谱法测定钢铁中的磷

研究了采用多元光谱拟合(MSF)功能ICP-AES法测定钢铁中磷的方法。采用MSF法扣除光谱干扰,选择波长为213.617nm的谱线作为磷的分析线,样品用硝酸(1+5)和浓盐酸溶解后可用ICP-AES直接测定。考察了仪器工作参数对测定结果的影响,确定了最佳工作条件:观测高度为13mm,雾化气流速为0.7L/min,射频功率为1300W。实验结果表明,方法的线性范围为0.05～100mg/L,线性相关系数为0.9998,检出限为0.0411mg/L,样品测定结果的相对标准偏差(RSD)为1.8%,加标回收率为96.1～100.8%。方法准确、快速,具有良好的精密度和准确度,可用于钢铁中磷的测定。     

Determination of phosphorus in steel by the combined technique of laser induced breakdown spectrometry with laser induced fluorescence spectrometry

Laser induced breakdown spectrometry (LIBS) combined with laser induced fluorescence spectrometry (LIFS) has been applied for detection of trace-level phosphorus in steel. The plasma induced by irradiation of Nd:YAG laser pulse for ablation was illuminated by the 3rd harmonic of Ti:Sapphire laser tuned to one of the resonant lines for phosphorus in the wavelength region of 253–256 nm. An excitation line for phosphorus was selected to give the highest signal-to-noise ratio. Fluorescence signals, P213.62 and P214.91 nm, were observed with high selectivity at the contents as low as several tens µg g^− 1. Fluorescence intensities were in a good linear correlation with the contents. Fluorescence intensity ratio of a collisionally assisted line (213.62 nm) to a direct transition line (214.91 nm) was discussed in terms of the analytical conditions and experimental results were compared with a calculation based on rate equations. Since the fluorescence signal light in the wavelength range longer than 200 nm can be transmitted relatively easily, even through fiber optics of moderate length, LIBS/LIFS would be a versatile technique in on-site applications for the monitoring of phosphorus contents in steel.     

王水溶解-电感耦合等离子体发射光谱法测定铁矿石中的微量磷

样品经王水分解后,在电感耦合等离子体发射光谱仪上测定了样品溶液中磷的含量。通过实验确定了基体元素的干扰、酸度、样品提升量、雾化气流速、功率、观测高度、分析谱线等分析条件。通过铁的干扰实验结果表明,样品中的基体元素铁不影响磷含量的测定。在用Ｐ178.222 nm分析线测定时,方法的检出限为P 0.0006％（相对于0.1ｇ样品,定容至100 mL）,相对标准偏差在3.14%～6.04％（ｎ＝11）,样品加标回收率在92%～110%。方法测定样品中磷含量的结果同光度法测定结果对比数据相符。     

Determination of phosphorus in fertilizers by inductively coupled plasma atomic emission spectrometry

An inductively coupled plasma atomic emission spectrometry (ICP-AES) method was developed for the determination of phosphorus in fertilizers. Total phosphorus, direct extraction available phosphorus (EDTA), and water-soluble phosphorus, reported as phosphorus pentoxide (P205), in 15 Magruder check fertilizers were measured by ICP-AES, and the results were compared with those obtained by the AOAC official method. Five analytical wavelengths of phosphorus, 177.499, 178.287, 213.618, 214.914, and 253.565 nm, were tested for the determination of phosphorus in fertilizers, and their detection limits were obtained. Acid effects of perchloric acid and possible matrix effects of aluminum, calcium, magnesium, potassium, and sodium were negligible for phosphorus determination. Wavelength 213.618 nm was the best analytical wavelength for phosphorus determination by all 3 sample preparation methods for the selected Magruder fertilizers. The results demonstrated that the accuracy and precision of the ICP-AES method were comparable with those of the official methods.     

Characterization of Plasma-Polymerized 4-vinyl Pyridine with Silver Nanoparticles on Poly(ethylene terephthalate) Film for Anti-Microbial Properties

4-vinyl pyridine was polymerized on poly(ethylene terephthalate) (PET) film by using lower energy pulsed AC plasma under low pressure in Ar atmosphere. The plasma polymerized coating was characterized by ATR Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Different thicknesses of poly(4-vinyl pyridine) coating under different plasma polymerization conditions were studied. Silver nanoparticles with diameter around 50nm deposit were precipitated on the poly(4-vinyl pyridine) coating by UV irradiation in Silver nitride water solution, in order to enhance the anti-microbial properties. Different kinds of modified PET films were tested for anti-microbial properties against yeast (Debaryomyces hansenii) by using microbiological analyser µ-4200 and direct microscopic count method.     

Determination of rifampicin in rat plasma by modified large‐volume direct injection RAM‐HPLC and its application to a pharmcokinetic study

A direct large volume injection high‐performance liquid chromatography (HPLC) method with homemade restricted‐access media (RAM) pre‐column and combined with a column‐switching valve was established and developed for determination rifampicin (RIP) in rat plasma. The rat plasma samples (100 μL) were injected directly onto pre‐column, where RIP was retained and pre‐concentrated, while proteins were washed to waste using a methanol–water (5:95) as the mobile phase at a flow rate of 1 mL/min. Then, by rotation of the switching valve at 5 min, the RIP were eluted from the pre‐column and transferred to an Luna C₁₈ analytical column by the chromatographic mobile phase consisting of methanol–acetonitrile–10 mm ammonium format (60:5:35) at a flow rate of 1 mL/min. The total analytical run time was 15 min with UV detection wavelength at 254 nm. Carbamazepine was used as the internal standard. Excellent linear correlation (r = 0.9993) was obtained in the range of 0.25–8 µg/mL for rat plasma. The intra‐day and inter‐day precisions of RIP were all <5.0%. The recoveries were in the range of from 99.98–113.66% for plasma. This on‐line RAM‐HPLC method was successfully applied to the pharmacokinetic study of RIP in rat plasma. Copyright © 2014 John Wiley & Sons, Ltd.     

电感耦合等离子体原子发射光谱法测定高温合金中低含量钇

建立电感耦合等离子体原子发射光谱法测定高温合金中低含量钇的方法。采用盐酸、硝酸、氢氟酸溶解样品,在优化的仪器条件下,采用基体匹配法配制系列标准工作溶液,选择分析线为360.073 nm。钇的含量在0.0005%~0.050%范围内与光谱强度具有良好的线性关系,相关系数为0.99999,检出限为0.000003%。该方法测定结果的相对标准偏差不大于6.0%(n=8),加标回收率为90.0%~104.0%。该方法简便、快速、准确,可用于高温合金中低含量钇的测定。     

Direct injection HPLC method for the determination of selected phenothiazines in plasma using a Hisep column

A direct plasma injection HPLC method has been developed for the determination of selected phenothiazines (promethazine, promazine, chlorpromazine) using a Hisep column. The method is easy to perform and requires 20 microL of a filtered plasma sample. The chromatographic run time is less than 11 min using a mobile phase of 15:85 v/v acetonitrile-0.18 m ammonium acetate pH 5.0 and UV detection at 254 nm. The method is linear in the concentration range 0.1-25 microg mL(-1) (r > 0.99, n = 6) for each analyte with RSD less than 6%. Interday and intraday variability were found to be < or =14%. The limits of detection and quantitation were 0.1 (S/N > 3) and 0.25 microg mL(-1) (S/N > 10), respectively, for each of the three phenothiazines. We can also apply this method to separate three other phenothiazines (ethopromazine, trifluoroperazine, prochlorperazine), although it lacks the selectivity to determine the concentration of all six drugs concurrently. The separation is feasible using these drugs in certain combinations.     

电感耦合等离子体质谱(ICP-MS)法测定高纯砷中痕量磷和硒

通过对样品前处理方式、内标元素及质量数的选择、仪器检测模式等方面进行优化,采用串联四级杆电感耦合等离子体质谱仪直接测定高纯砷中痕量的磷和硒.实验室使用电子级盐酸、硝酸配制王水直接溶解样品,在不除基体的情况下,以铑作为内标补偿校正砷基体的抑制效应,在调试好的仪器上进行测定磷、硒含量.磷、硒的测定结果相对标准偏差(RSD)...     

Analysis of superconductor oxides YBa2Cu3O8−x by inductively coupled plasma atomic emission spectrometry and complexometric titration

The elemental composition of superconductor oxides YBa₂Cu₃O_8−x were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and complexometric titration. Samples were dissolved in dilute HCl. A sequential PU 7000 Philips inductively coupled plasma atomic emission spectrometer was used for the measurements. A comparison of the different atom and ion emission lines of yttrium, barium and copper was carried out. The effect of changes of forward radio frequency (RF) power coupled into the plasma on emission intensity of various spectral lines was studied. The RF power was changed from 0.8 to 1.2 kW. The changes in the net intensities (%) of the emission lines of Cu(I) at 324.754 nm, Cu(II) at 224.700 nm, Ba(II) at 455.403, Ba(II) at 493.409 nm, Y(II) at 371.030 nm and Y(II) at 360.073 nm were calculated. The indicator 1-(2-Pyridylazo)-2-Naphthol (PAN) and different buffers were used for the complexometric titration of Cu, Y and Ba. No statistically significant differences were found between the results of ICP-AES and chemical methods of analysis.     

Determination of Riboflavin in Human Plasma by Excitation‐Emission Matrix Fluorescence and Multi‐Way Analysis

Direct determination of riboflavin (Fig. 1), a vitamin, in human plasma was accomplished based on excitation‐emission matrix (EEM) fluorescence measurements and multi‐way chemometrics method based on parallel factor analysis (PARAFAC). The PARAFAC trilinear model, without restrictions and using one factor was used in the data analysis. The excitation wavelength range was from 380 to 460 nm and the emission was recorded from 480 to 600 nm. The calibration set was constructed with sixteen standard solutions in a concentration range of 0.02–0.38 μg mL^?1 for riboflavin. The capabilities of the method for the analysis were evaluated by determination of riboflavin in synthetic and real samples with satisfactory results. The accuracy of the methods, evaluated through the root mean square error of prediction (RMSEP), was 0.0059 for riboflavin by the PARAFAC model. Also, partial least squares (PLS) model was built at one excitation wavelength and used to determine a set of synthetic and real samples. The best model was obtained with PARAFAC. This result shows that molecular fluorescence spectroscopy can be used for the development of robust analytical methods for the direct determination of riboflavin in complex backgrounds such as human plasma.     

Temporal behavior of neutral and ionic lines emitted from a laser induced plasma on an aqueous surface

The temporal behavior of spectral lines emitted from a laser induced plasma has been studied. The plasma was created by using a Nd:YAG pulsed laser in air at atmospheric pressure focused on the surface of an aqueous solution. This work is an extension of previous published work [J. Ben Ahmed, Z. Ben Lakhdar, G. Taieb, Kinetics of laser induced plasma on an aqueous surface, Laser chem. 20 (2002) 123–134.]. The time evolution of lines intensities emitted from Ca, Ca⁺, Mg and Mg⁺ has been experimentally observed and simulated using a simple theoretical approach based on electron–ion recombination. It was shown that the plasma temperature and electron density are correlated to the dynamics of plasma emission. Finally, the time evolution of the optical depth of Ca⁺ resonance line at 393.4 nm was also studied.     

High‐performance liquid chromatography with solid‐phase extraction for the quantitative determination of nilotinib in human plasma

A simple, rapid and sensitive high‐performance liquid chromatography (HPLC)‐based method with ultraviolet detection was developed for the quantitation of nilotinib, a tyrosine kinase inhibitor, in human plasma. Nilotinib and the internal standard dasatinib were separated using a mobile phase of 0.5% KH₂PO₄ (pH2.5)–acetonitrile–methanol (55:25:20, v/v/v) on a Capcell Pak MG II column (250 × 4.6 mm) at a flow rate of 0.5 mL/min and optical measurement at 250 nm. Analysis required only 100 μL of plasma and involved a rapid and simple solid‐phase extraction with an Oasis HLB cartridge, which gave recoveries from 72 to 78% for nilotinib and from 74 to 76% for dasatinib. The lower limit of quantification for nilotinib was 10 ng/mL. The linear range of this assay was between 10 and 5000 ng/mL (r² > 0.9992 for the regression line). Intra‐ and inter‐day coefficients of variation were less than 10.0% and accuracies were within 10.4% over the linear range. Our results indicate that this method is applicable to the monitoring of plasma levels of nilotinib in a clinical setting. Copyright © 2009 John Wiley & Sons, Ltd.     

Comparison in the analytical performance between krypton and argon glow discharge plasmas as the excitation source for atomic emission spectrometry

The emission characteristics of ionic lines of nickel, cobalt, and vanadium were investigated when argon or krypton was employed as the plasma gas in glow discharge optical emission spectrometry. A dc Grimm-style lamp was employed as the excitation source. Detection limits of the ionic lines in each iron-matrix alloy sample were compared between the krypton and the argon plasmas. Particular intense ionic lines were observed in the emission spectra as a function of the discharge gas (krypton or argon), such as the Co II 258.033 nm for krypton and the Co II 231.707 nm for argon. The explanation for this is that collisions with the plasma gases dominantly populate particular excited levels of cobalt ion, which can receive the internal energy from each gas ion selectively, for example, the 3d⁷4p ³G₅ (6.0201 eV) for krypton and the 3d⁷4p ³G₄ (8.0779 eV) for argon. In the determination of nickel as well as cobalt in iron-matrix samples, more sensitive ionic lines could be found in the krypton plasma rather than the argon plasma. Detection limits in the krypton plasma were 0.0039 mass% Ni for the Ni II 230.299-nm line and 0.002 mass% Co for the Co II 258.033-nm line. However, in the determination of vanadium, the argon plasma had better analytical performance, giving a detection limit of 0.0023 mass% V for the V II 309.310-nm line.     

Determination of phosphorous in organic compounds and metal complexes by inductively-coupled plasma atomic emission spectrometry

Phosphorus is determined by inductively-coupled plasma atomic emission spectrometry at 213.618 nm. Different types of organic and inorganic phosphorus compounds and metal complexes were examined after direct dissolution in water, aqueous ethanol or acid, or after decomposition by oxygen flask combustion or Kjeldahl digestion; results were within the usual limit of precision and accuracy for such determinations. The effect of small (<20%) ethanol concentrations in the aqueous solution on the signals obtained from a low-power (1200 W) argon plasma is examined and discussed.     

Spectral measurements of inductively coupled and helicon discharge modes of a laboratory argon plasma source

An experimental study was conducted to investigate the effects of several operational parameters in the emission spectra, in the 400-850 nm wavelength region, of a laboratory Argon plasma source. In particular, the emission spectra of the inductively coupled plasma and the Helicon plasma modes of operation were compared. Comparisons of spectra point to a significant increase in the ionization fraction of the plasma for the Helicon mode of operation. The spectral measurements allow one to determine the major trends in the plasma electron density for various parameters such as power delivered to the helical antenna, propellant mass flow rate, and applied external magnetic field intensity.Analysis of a prominent Argon single ion line, at 434.8 nm, points out that the plasma electron density increases linearly with the power delivered to the helical antenna, and that there is an optimum propellant mass flow rate for maximum ionization fraction. Additional analysis of the same line shows that above a minimum applied axial magnetic field intensity, the variation in the magnetic field strength has little effect on the plasma electron density.     

Determination of ng ml-1 levels of phosphorus in waters by diisobutyl ketone extraction and inductively coupled plasma atomic emission spectrometry

Reduced molybdoantimonylphosphoric acid is extracted into diisobutyl ketone (DIBK) and phosphorus in the extract determined by i.c.p. emission spectrometry at the P I 214.91-nm line. The Mo II 213.61 nm line interfered with the P I 213.62-nm line. The method is applied to 0.2–200 μg of phosphorus in 500 ml of river or sea water. Arsenic(III), Si, Ge, Fe(III) and most anions do not interfere, but As(V) >10 × P) causes positive errors. The detection limit is 0.37 ng P ml^-1, and the relative standard deviation for 5 μg of phosphorus is 2.1%.     

High Pressure Liquid Chromatographic Determination of Mecillinam in Human Plasma and Urine

Abstract

A simple, specific, rapid and sensitive method for the analysis of mecillinam in plasma and urine using high pressure liquid chromatography is described. The assay is performed by direct injection of a plasma protein free supernatant or a dilution of urine. A μBondapak phenyl column with an eluting solvent of 16% CH₃CN-0.2% H₃PO₄ was used, with UV detection of the effluent at 220 nm. Desacetyl-cephalothin was used as the internal standard and quantitation was based on peak height ratio of mecillinam to that of the internal standard. The lowest concentration detectable without extraction was 0.25 μg/ml for plasma and 8.9 μg/ml for urine. No interference from plasma and urine was noted.     

A rapid and selective HPLC‐UV method for the quantitation of efavirenz in plasma from patients on concurrent HIV/AIDS and tuberculosis treatments

Owing to heterogeneity in therapeutic response, efavirenz is of research and clinical interest. There is a need to quantitate it using noncostly and selective methods. A method for efavirenz quantitation in plasma containing HIV and tuberculosis drugs was developed. Chromatographic separation was carried out using a C₁₈ column. The mobile phase consisted of 0.1% formic acid and acetonitrile, and was pumped at a flow rate of 0.3 mL/min. Efavirenz and ritonavir (internal standard) were monitored at 247 nm. Plasma proteins were precipitated by centrifugation. The analysis time was 6 min. The response was linear (r = 0.9997). The accuracy ranged between 98 and 115% (intraday) and between 99 and 117% (interday). The precision ranged from 1.670 to 4.087% (intraday) and from 3.447 to 13.347% (interday). Recovery ranged from 98 to 132%. Stability ranged between 99 and 123%. The selectivity was proven by analysis of drugs used for the management of HIV/AIDS and tuberculosis. Plasma sample analysis showed an efavirenz retention time of 5.57 min and a peak plasma concentration of 2.4 µg/mL occurring at 2 h. This method is rapid and selective, and thus suitable for monitoring efavirenz in patients with HIV/AIDS alone or co‐infected with tuberculosis in a less resourced setting. Copyright © 2013 John Wiley & Sons, Ltd.     

Simultaneous determination of sulfamethoxazole and trimethoprim in human plasma by capillary zone electrophoresis

A capillary electrophoretic method for the simultaneous determination of sulfamethoxazole and trimethoprim in plasma was developed. Sulfamethoxazole and trimethoprim extracted from human plasma with ethyl acetate were analyzed at 20 kV and 25 degrees C using 15 mm phosphate buffer (pH 6.2) as the electrolyte. The detection was by UV at 220 nm. The run time was 8.0 min and the limit of quantification was 10.00 microg/mL for sulfamethoxazole and 2.00 microg/mL for trimethoprim. The recovery was >99% for both compounds. This method enabled the detection of sulfamethoxazole and trimethoprim in plasma of patients after oral ingestion of their combined formulation. The present simple and rapid method is applicable to drug monitoring in immunocompromised patients who are taking the combined formulation of these compounds for the treatment or prophylaxis of Pneumocystis carinii pneumonia.