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ICP–AES法测定低合金钢中的微量硼 总被引:2,自引:0,他引:2
采用电感耦合等离子体发射光谱法(ICP–AES)测定低合金钢中硼元素的含量。采用密闭微波消解法对样品进行溶解,考察了铁基体元素和共存元素对硼元素测定的影响,确定了硼元素的分析线为208.959 nm,通过基体匹配消除基体的影响。硼的质量浓度在0~5.00μg/m L范围内与谱线强度呈良好的线性,相关系数r2=0.999 9,方法检出限为0.004μg/m L,加标回收率为96%~103%,测定结果的相对标准偏差为1.5%~2.9%(n=8)。该方法具有较高的灵敏度和准确度,满足低合金钢中硼元素的分析要求。 相似文献
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在pH 1.85的HCl-NaAc缓冲溶液中,荧光桃红与盐酸异丙嗪依靠静电引力和疏水作用力相互作用形成离子缔合物,其组成比为1∶2,最大褪色波长537 nm,表观摩尔吸光系数ε=4.07×104L.mol-1.cm-1,研究了体系的光谱特征,适宜的反应条件和影响因素,发现体系的吸光度与盐酸异丙嗪的质量浓度在0.04~3.6μg/mL范围内呈良好的线性关系,线性回归方程A=-0.04991-0.1269ρ(μg/mL),线性相关系数r=0.9998,检出限和RSD分别为0.0177μg/mL和2.2%。本法可用于药物制剂中盐酸异丙嗪含量的快速测定。 相似文献
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Cimetidine reacting with 1,5-dichloroanthraquinone in acetone solution can produce a charge-transfer complex that shows a strong absorption peak at 343 nm. The absorption value at 343 nm increased with cimetidine concentration in the range of 0.01—0.5 μg/mL, with regression coefficient of 0.9995 and detection limit of 0.006 μg/mL. This simple and sensitive method has been successfully applied to determine cimetidine in tablets and capsules, with average recovery of (98.47±0.92)% and (97.07±1.16)%, respectively. Furthermore, the mole ratio of the complex between cimetidine and 1,5-dichloroanthraquinone is 2∶1, and the mechanism of charge-transfer reaction is explored. 相似文献
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基于0.004 mol/L的柠檬酸介质中,痕量V(Ⅴ)催化KBrO3氧化甲基紫的褪色反应,建立了测定痕量V(Ⅴ)的动力学光度法。方法的检出限为1.23μg/L,线性范围为0~0.16μg/mL。讨论了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响,确定了该体系反应的最佳条件。在25 mL溶液中,测定2.0μg V(Ⅴ)的RSD为1.9%(n=11)。方法可用于测定小麦和苹果中的痕量V(Ⅴ),RSD为1.1%~2.7%,标准加入回收率为97.6%~99.0%。 相似文献
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用分光光度法研究了精氨酸与2,3-二氯-5,6-二氰-1,4-苯醌(DDQ)的荷移反应。实验表明,在硼砂溶液中,精氢酸与DDQ在室温下反应30min可获得稳定的络合物,其组成比为2∶1,λmax=342nm,表观摩尔吸光系数ε=1.65×104 L.mol-1.cm-1,线性范围为2~30μg/mL。应用拟定的方法测定了盐酸精氨酸注射液的含量,结果与文献方法一致,回收率在97.2%~98.1%之间,相对标准偏差小于3.1%。 相似文献
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研究了吐温20(Tween20)存在下,铝与二甲酚橙(XO)的显色反应,建立了分光光度法测定微量铝的新方法.结果表明,在pH=3.13的乙酸-乙酸钠缓冲介质中,铝与XO及吐温20反应生成有色络合物,络合物的最大吸收波长位于511 nm处, 表观摩尔吸光系数ε为1.99×10~4 L·moL~(-1)·cm~(-1),在10 mL溶液中,铝量在2.2~15.1 μg范围内符合比耳定律,检出限为0.0018 μg/mL.方法应用于茶叶、沙棘叶中铝的测定,样品加标回收率为96%~102.6%. 相似文献
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Hui Chen Li Li Min Zhou Yong Jun Ma College of Chemistry Chemical Engineering Gansu Key Laboratory of Polymer Materials Northwest Normal University Lanzhou China 《中国化学快报》2008,19(2):203-206
A high sensitive flow-injection chemiluminescence (FI-CL) method for the determination of tryptophan has been developed. The method is based on the chemiluminescence reaction of galangin-potassium permanganate-tryptophan in polyphosphoric acid (PPA) media. Under the optimized conditions, tryptophan was determined in the range 0.05-10 μg/mL with the detection limit (3tr) of 5.0 × 10^-3 μg/mL. The relative standard deviation (RSD) was 1.0% for 11 replicate determinations of 1.0 μg/mL tryptophan. Three synthetic samples were determined selectively with recoveries in the range from 99.6% to 102.0% in the presence of other amino acids. 相似文献
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A novel chemiluminescent method for the determination of salicylic acid in bactericidal solutions 总被引:2,自引:0,他引:2
A new flow-injection procedure has been developed for the determination of salicylic acid based on the enhancement of the chemiluminescence from the cerium(IV)-Tween 20 reaction by salicylic acid in acidic medium. The method is simple, selective and sensitive with a detection limit of 2.5x10(-9) g mL(-1). It is applicable to the determination of salicylic acid in the concentration range of 4.0x10(-9)-1.1x10(-6) g mL(-1). The relative standard deviation (RSD) is 0.85% for 4.0x10(-7) g mL(-1) salicylic acid (n=11). The method has been successfully applied to the determination of salicylic acid in bactericidal solutions. Furthermore, it is suggested that light emission from cerium(IV)-Tween 20 reaction is probably because of the formation of singlet oxygen 1O2* and the emitter is excited oxygen molecular pairs O2(1delta(g))O2(1sigma(g)-). 相似文献
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E. G. Khomutova V. A. Zagorodnikova S. A. Zagorodnikova O. I. Ostanina 《Journal of Analytical Chemistry》2013,68(7):611-615
A catalytic method has been developed for the individual determination of trace iridium and rhodium using the oxidation of sulfarsazene by potassium periodate as an indicator reaction in a flow-injection system. The analytical range is from 0.10 to 2.0 μg/mL iridium and from 0.0010 to 0.027 μg/mL rhodium. The detection limits are 0.0074 μg/mL iridium and 0.00095 μg/mL rhodium; the determination error does not exceed RSD = 4% in model solutions. The method is selective in the presence of the majority of colored and platinum-group metals. The accuracy of the results has been confirmed by the standard addition method. 相似文献
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Gang Sun Xingguo Chen Qianfeng Li Huaiwen Wang Yongyao Zhou Zhide Hu 《Analytical and bioanalytical chemistry》2000,367(3):215-219
A new method is proposed for the spectrophotometric determination of Pd(II), based on the reaction of Pd(II) with 2-(4-chloro-2-phosphonophenylazo)-7-(3-carboxyphenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid(CPA-mK) in sulfuric acid without heating. Beer’s law is obeyed for 1.0–4.0 μg of Pd (II) in 10 mL of solution. The calibration curve from 1.0 to 42.0 μg in 10 mL of solution is modeled successfully by artificial neural networks (ANNs). The maximum relative error between experimental values and the values predicted by ANNs is 1.5%. In comparison with some mathematical functions, ANNs show better ability for curve fitting, thus greatly extending the applicable range of the calibration curve of this new system. The method has been applied to determine Pd (II) in ore and catalyst samples with a relative error of less than 4% and with a recovery range between 94% and 103%. 相似文献
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A simple, rapid, cost effective and extraction‐free spectrophotometric method has been developed for the determination of zolmitriptan in pharmaceutical raw and dosage forms. The method is based on the charge‐transfer reaction of zolmitriptan in acetonitrile medium with 0.2% 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone to form a colored product peaking at 555 nm. Beer's law is obeyed in the concentration range 10‐250 μg mL?1 with molar absorptivity of 1.7 × 103 L mole?1 cm?1. The effects of variables such as reagent concentration, time of reaction, color stability and interferences have been investigated to optimize the procedure. The results have been validated analytically and statistically. The proposed method has been successfully applied for the determination of zolmitriptan in pharmaceutical formulations. Results indicate that the method is accurate, precise and reproducible (relative standard deviation < 2%). 相似文献
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以R(-)-4-N,N-二甲基磺酰胺-7-(3-异氰酸吡咯烷)-2,1,3-苯并氧杂咪唑(R(-)-DBD-PyNCS)为手性荧光衍生化试剂,成功地拆分了甲状腺素对映体D,L-四碘甲状腺原氨酸(T4)和L-三碘甲状腺原氨酸(T3)。在反应温度为40 ℃、反应时间为20 min时,R(-)-DBD-PyNCS在碱性介质中可与甲状腺素对映体生成稳定的非对映体衍生物。该衍生物在以乙腈-水-醋酸(体积比为60∶40∶1)为流动相,流速为1.0 mL/min,色谱柱为Intersil-ODS-3 C18柱(150 mm×4.6 mm,5 μm)的色谱条件下得到了充分的分离。采用荧光检测器在激发波长460 nm、发射波长550 nm下检测。D,L-T4和L-T3分别在0.016~0.30 μg/μL和0.0067~0.22 μg/μL范围内,峰面积与浓度呈良好的线性关系(r>0.999)。D,L-T4和L-T3的最低检出限分别为0.02 μg/mL和0.85 μg/mL(S/N=3)。在D-T4、L-T4、L-T3质量浓度分别为0.10 μg/μL下测得峰面积的相对标准偏差分别为3.40%,1.63%,3.30%(n=7)。该方法成功地应用于甲状腺片中T4和T3的含量测定。 相似文献
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A 4-aminonaphthalimide-based ratiometric fluorescent probe 1 employing the internal charge transfer (ICT) mechanism was designed and synthesized to detect bovine serum albumin (BSA). The interaction of 1 and BSA was investigated by fluorescence and UV-vis absorption spectroscopy. Upon treatment with BSA, the probe successfully exhibited a ratiometric fluorescent response at 540 nm and 480 nm. The fluorescent intensity ratio at 540 nm and 480 nm (F(540)/F(480)) increases linearly with BSA concentration in the range of 0-75.0 μg mL(-1) and the detection limit was about 2.4 ng mL(-1). Our strategy is expected to provide a methodology to quantify BSA either by a normal or by a ratiometric and colorimetric way with high sensitivity. 相似文献
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A d.c. arc emission spectrographic method has been developed for the determination of nine trace impurities in boron nitride. The charge for exciting the sample contains equal quantities of boron nitride and graphite (containing 2% NaF as carrier and 1% La(2)O(3) as an internal standard). The method is useful in the determination of impurities in the range 2-1000 ppm, with a mean relative standard deviation of 13%. 相似文献
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高碘酸钾氧化中性红褪色催化动力学光度法测定痕量硒(Ⅳ) 总被引:1,自引:0,他引:1
基于3.2×10-4mol/LH2SO4介质中,痕量硒(Ⅳ)催化KIO4氧化中性红的褪色反应,建立了测定痕量硒(Ⅳ)的动力学光度法。在固定加热时间段(6min)后,于530nm处测定中性红的吸光度降低值监控反应速率。方法检出限为0.36μg/L,校准曲线的质量浓度线性范围为0~8.0μg/L。实验了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响。研究了反应的最佳条件,并测定了一些动力学参数,催化反应的表观活化能为81.60kJ/mol。11次重复测定0.1μg/25mL和0.2μg/25mLSe(Ⅳ)的相对标准偏差分别为2.1%和1.9%。方法用于食品和人发样品中痕量硒(Ⅳ)的测定,相对标准偏差为0.33%~3.8%,加标回收率为96.0%~103.0%。 相似文献
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凝胶渗透色谱-气相色谱串联质谱法测定动物脂肪中164种农药残留 总被引:7,自引:1,他引:7
建立了气相色谱-串联质谱法(GC-MS-MS)同时测定动物脂肪中164种农药的多残留分析方法。样品经乙腈均质提取2次,合并提取液并在45℃水浴中旋转浓缩至1 mL,加入5 mLV(环己烷)∶V(乙酸乙酯)=1∶1进行溶剂交换2次后,用V(环己烷)∶V(乙酸乙酯)=1∶1稀释至10 mL,用凝胶渗透色谱(GPC)净化,GC-MS-MS多反应监测模式(MRM)测定,内标法定量。本方法研究的164种农药的线性相关系数为0.9438~1.0000,其中有154种在0.9900以上,占总数的93.9%。方法检出限(S/N≥3)为0.1~360.0μg/kg,其中在10.0μg/kg以下的有121种,占研究农药总数的73.8%。用猪、鸡、牛、羊4种不同的脂肪在低、中、高3个添加水平评价了164种农药的方法效率,其中有150种的回收率在70%~120%之间,相对标准偏差(RSDs)在20%以内。本方法适用于不同动物脂肪中150种农药多残留的定量测定和14种农药的定性测定。 相似文献
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Erdem A Muti M Papakonstantinou P Canavar E Karadeniz H Congur G Sharma S 《The Analyst》2012,137(9):2129-2135
We present a graphene oxide (GO) integrated disposable electrochemical sensor for the enhanced detection of nucleic acids and the sensitive monitoring of the surface-confined interactions between the anticancer drug mitomycin C (MC) and DNA. Interfacial interactions between immobilized calf thymus double-stranded (dsDNA) and anticancer drug MC were investigated using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Based on three repetitive voltammetric measurements of 120 μg mL(-1) DNA immobilized on GO-modified electrodes, the RSD % (n = 3) was calculated as 10.47% and the detection limit (DL) for dsDNA was found to be 9.06 μg mL(-1). EIS studies revealed that the binding of the drug MC to dsDNA leads to a gradual decrease of its negative charge. As a consequence of this interaction, the negative redox species were allowed to approach the electrode, and thus increase the charge transfer kinetics. On the other hand, DPV studies exploited the decrease of the guanine signal due to drug binding as the basis for specifically probing the biointeraction process between MC and dsDNA. 相似文献