磷锑钼蓝分光光度法测定氟硅酸中的磷酸根

建立磷锑钼蓝分光光度法测定氟硅酸中磷酸根含量的方法。在氟硅酸样品中加入高氯酸高温挥发除去HF、SiF_4等挥发性的物质,在弱酸性的介质中磷与锑、钼酸铵形成杂多酸,用抗坏血酸还原为磷锑钼蓝络合物,用分光光度计在705nm波长下测定氟硅酸中磷酸根含量。研究了测定波长、样品酸度、还原剂浓度、还原时间、酒石酸锑钾用量、干扰元素对测定结果的影响,并确定了最佳分析条件:测定波长为705 nm,盐酸溶液(1+1)加入量为1.3 mL,酒石酸锑钾溶液(3 g/L)加入量为0.5 mL,抗坏血酸溶液(20 g/L)加入量为1.5 mL,还原时间为10 min。在此实验条件下,磷酸根的质量浓度在0～15 μg/mL与吸光度具有良好的线性关系,线性相关系数为0.999 8,检出限为0.051μg/mL。测定结果的相对标准偏差为2.27%～2.38%(n=11),加标回收率为97.34%～102.72%。该方法操作简单,测试结果准确度和精密度较高,可满足氟硅酸中磷酸根含量的测定,用于氟硅酸生产的质量控制。     

NaIO4-H2O2-盐酸异丙肾上腺素-Cu2+体系化学发光测定盐酸异丙肾上腺素

在磷酸介质中,过氧化氢存在下,加入少量Cu2+的盐酸异丙肾上腺素试液经80℃水浴加热处理后与高碘酸钠反应产生强烈的化学发光.据此,结合流动注射技术建立了一种测定盐酸异丙肾上腺素的化学发光分析新方法.方法的线性范围为1.0×10-9～7.0×10-7 g/mL,检出限为4.0×10-10g/mL,相对标准偏差为3.0%(1.0×10-8g/mL盐酸异丙肾上腺素,n=11).该法用于注射液中盐酸异丙肾上腺素的测定,回收率为97%～103%.     

高效液相色谱法测定烟草料液中防腐剂

采用高效液相色谱法测定烟草料液中防腐剂苯甲酸、山梨酸、对羟基苯甲酸乙酯的含量。样品用10 g.L乙酸溶液溶解,经Waters Sep-Pak-C18固相萃取小柱净化。以ZORBAXStable Bound色谱柱为固定相,2.0 g.L-1磷酸-乙腈(20+80)混合溶液为流动相,用二极管阵列检测器在250 nm处进行测定,三种防腐剂在2.5 min内可达到基线分离。方法的回收率为88.0%~101.0%,相对标准偏差(n=7)为3.1%~3.6%。     

甲醇-丙三醇消解离子色谱 (IC)测定高纯硼酸中硫酸根、磷酸氢根、锂、钠、钾、镁和钙离子

通过基体预消除法测定了高纯硼酸中痕量硫酸根、磷酸氢根、锂、钠、钾、镁和钙离子杂质组分。在特制的密闭反应容器中硼酸首先与甲醇生成易挥发性的硼酸三甲酯,硼酸三甲酯与丙三醇反应生成不易挥发的多聚硼酸酯,同时释放出甲醇,实现硼酸基体的消除。离子色谱法(IC)测定各组分的检测限(3σ)分别为硫酸根100 ng/g、磷酸根200 ng/g、Li+ 15 ng/g、Na+ 20 ng/g、K+ 30 ng/g、Mg2+ 50 ng/g和Ca2+ 50 ng/g。     

阳离子选择性耗尽进样-胶束电动色谱法对可非糖浆中盐酸异丙嗪与磷酸可待因的测定

在胶束电动色谱法的基础上,联用阳离子选择性耗尽进样技术,对盐酸异丙嗪和磷酸可待因同时测定的方法进行了研究。考察了pH值、有机溶剂、SDS浓度、进样时间、进样电压等实验条件对分离效果的影响。最佳实验条件为:缓冲体系16%乙腈+80 mmol/L SDS+20 mmol/L NaH2PO4(pH2.4),分离电压为-18 kV,测量波长214 nm,萃取液pH2.4,进样电压10 kV,进样时间100 s。在优化实验条件下,两种物质在8 min内出峰,峰面积RSD不大于4.6%。盐酸异丙嗪、磷酸可待因的线性范围分别为0.50~81.3、0.78~62.5μg/L,检出限分别为0.16、0.12μg/L,相关系数分别为0.998 9、0.998 8。将方法用于可非糖浆中盐酸异丙嗪与磷酸可待因的测定,回收率为96%~106%。     

CdTe量子点荧光猝灭法测定奥沙利铂中微量银

以谷胱甘肽作为稳定剂,100℃恒温回流,直接合成水溶性CdTe量子点。基于Ag+对合成的CdTe量子点的荧光猝灭效应,建立了测定抗癌药物奥沙利铂中微量银的方法。考察了量子点浓度、缓冲液种类、缓冲液浓度、缓冲液pH和反应时间对银离子测定的影响。当量子点浓度为0.004 g/L时,在0.10 mmol/LpH7.4的磷酸缓冲溶液中,反应时间为5 min,体系的相对荧光强度与Ag+的质量浓度呈良好的线性关系,其线性范围为16.42～98.50μg/L,线性相关系数为0.9975,检出限为0.12μg/L。     

碱熔-电感耦合等离子体发射光谱(ICP-OES)法测定钨锡矿石中钨锡钼铜铅锌硫砷

钨锡矿石共生与伴生元素多,为克服常用的钨锡矿石中锡、钨、钼、铜、铅、锌、硫、砷等8种元素检测过程程序繁琐,效率低下问题,通过在刚玉坩埚中直接加入氢氟酸挥发掉样品中的二氧化硅,用过氧化钠熔融已除硅的样品,再以酒石酸+磷酸+盐酸提取,解决了碱熔酸化的样品溶液中硅胶的影响和钨、锡等元素的不稳定性问题,建立了电感耦合等离子体发射光谱(ICP-OES)法直接测定样品中的锡、钨、钼、铜、铅、锌、硫、砷的方法。系统研究了过氧化钠熔剂的用量对各元素的影响,考察了引入单一酒石酸的络合作用和酒石酸+磷酸的混酸对各元素的影响,结果表明,过氧化钠用量为1.0 g时样品可以完全分解;单一酒石酸的络合作用有限,钨含量高的样品容易发生沉淀,而酒石酸+磷酸的混酸可以使钨在溶液中长期稳定,而对其他元素没有影响。选用5个钨、锡矿石国家一级标准物质按照本方法进行处理,测定结果均在认定值的误差范围内;采用4个实际样品与标准方法进行比对实验,各元素检测结果无显著差异。各元素的光谱强度在0～200 μg/mL浓度范围内呈良好的线性关系,相关系数（r）均在0.999 9以上,方法检出限值为3.0μg/g～25.0 μg/g,相对标准偏差RSD（n=12）为0.33%～7.0%。方法测试过程操作简便,检测结果准确、可靠,在多元素大批量的样品检测中具有明显优势。     

流动注射后化学发光法测定Ca~(2+)

实验发现Ca2+在铁氰化钾-钙黄绿素化学发光反应体系中的后化学发光反应.优化了反应条件,建立了一种利用后化学发光反应测定Ca2+的流动注射化学发光分析法.方法的线性范围为1.0×10-6～1.0×10-4 g/mL,检出限为3.0×10-7 g/mL, 相对标准偏差为1.8%(2.0×10-5 g/mL Ca2+,n=11).此法已用于自来水中Ca2+含量的测定,结果与标准方法测定值一致.     

光度法快速测定锰铁中锰

锰铁中锰元素的测定一般都是选用磷酸-三价锰滴定法.用光度法测定锰铁中锰尚未见报道.本文采用在硫酸、磷酸介质中,用高碘酸钾将锰氧化成七价,用等滴光度法测量其吸光度.该方法使用试剂种类少,溶样氧化速度快,且操作简便快速.1 试验部分1.1 仪器72G型分光光度计(上海分析仪器厂)1.2 试验方法称取试样10mg于150ml三角瓶中,加磷酸5ml,加热溶解,稍冷,加入硫酸(1+20)80ml,高碘酸钾1g,继续加热煮沸4～5min,使锰显色完全.停止加热,流水冷至室温,移入100ml量瓶中,以水稀释至刻度,摇匀.     

气相色谱-质谱法测定奶嘴中磷酸苯酚酯

提出了气相色谱-质谱法检测奶嘴中3种磷酸苯酚酯[磷酸三甲苯酯(TCP)、磷酸甲苯二苯酯(CDP)和磷酸三-二甲苯酯(TXP)]的方法。试样经乙酸乙酯提取后,在35℃水浴中在40℃旋转蒸发仪中浓缩后,用甲醇溶解定容至2.0mL,通过DB-1701石英毛细管色谱柱(30m×0.25mm,0.15μm)分离,采用电子轰击离子源选择离子检测模式进行质谱测定。3种磷酸苯酚酯质量浓度均在30.0～500μg.L-1内与其峰面积呈线性关系,测定下限(10S/N)为30μg.kg-1。以奶嘴样品为基体加入3种浓度水平的混合标准溶液按方法测定后,求得方法的回收率在64.0%～88.5%之间,相对标准偏差(n=10)为0.86%～8.7%。     

流动注射热焓法测定浸取磷酸中三氧化硫

以测量钡离子与硫酸根离子沉淀反应热效应的热焓法为基础,采用合并带流路建立了测定浸取磷酸中三氧化硫的流动注射热焓法。该法在４．０－４２．０ｇ／Ｌ范围内可准确测定了ＳＯ３的含量。相对标准偏差为１．６％,标准加入回怍率为９６％－１０４％;测样速度为６０样／ｈ。     

Determination of polonium-210 in phosphoric acid

Polonium-210 in phosphoric acid has been recognized as a significant source of alpha contamination of processed Si-wafers for memory devices of computer. In the present work, a convenient method was developed for the determination of trace²¹⁰Po in phosphoric acid of high purity. For the determination,²⁰⁹Po was used as a yield tracer. The present method consists of (1) addition of the tracer to 5 ml aliquot of phosphoric acid sample, (2) pH adjustment (to 2) of the sample solution to make up electrolytic solution, (3) electrodeposition for the simultaneous achievement of Po separation and preparation of counting source on stainless-steel disc, and (4) alpha-ray spectrometry. By the developed method, more than 95% of Po was separated from phosphoric acid sample onto counting disc. The minimum detectable radioactivity of²¹⁰Po in 5 ml of phosphoric acid was about 0.03 mBq by counting the electrodeposited alpha-activity for 10 days under a counting efficiency of ≈30%.     

食品添加剂磷酸中钠含量测定方法研究

由于磷酸中钠的含量极低,又不能过多地稀释,因而受基体和背景以及黏稠度的影响很大,为用火焰原子吸收光谱法测定钠,采用标准加入曲线法测定,并进行了精密度、准确度和检出限的测定试验,以及进行实验室间样品中钠含量的测比对。试验结果表明,该法能够快速、准确地测定磷酸中钠含量,结果令人满意。     

Dissolution of sintered thorium dioxide in phosphoric acid using autoclave and microwave methods with detection by gamma spectrometry

A quantitative and fast method of dissolution of refractory thoria (ThO₂) was developed for the determination of thorium (Th) in a given sample. The dissolution of sintered ThO₂ powder, microspheres and pellets using 88% phosphoric acid was investigated. The conditions of quantitative dissolution of ThO₂ microspheres were optimized by conventional heating in autoclave and also by microwave heating. 100 mg of sintered ThO₂ microspheres were dissolved in 8 g of phosphoric acid in an autoclave, and heating at 170 °C for 3 h, in comparison to 5 g of phosphoric acid by microwave heating (375 W) at 220 °C for 1 h. Dissolution studies on the powder form of sintered ThO₂ were also performed. 1 g of sintered ThO₂ powder could be dissolved in 6.5 g of phosphoric acid in autoclave heating at 170 °C for 1 h. Strong complexing of (PO₄)³⁻ with Th⁴⁺ may be the influencing factor for quantitative dissolution of ThO₂.     

电感耦合等离子体发射光谱法测定锗精矿中锗量

建立了用硝酸、氢氟酸、磷酸溶解样品,电感耦合等离子体发射光谱法测定锗精矿中锗量的方法。试验选择209.426nm作为最优分析谱线,锗的检出限为0.006μg/mL,测定下限为0.020 μg/mL,在磷酸基体匹配的条件下测定,测定范围为1%-15%,与经典碘酸钾滴定法对比,数据一致,相对标准偏差<3%(n=11),加标回收率98%~101%,能够满足快速测定及批量处理锗精矿中1%-15%的锗含量的需求。     

连续流动分析法测定土壤中的挥发酚

建立了连续流动分析仪测定土壤中挥发酚含量的方法。称取5 g左右的土壤样品,以磷酸调节p H值为4,加入适量水并进行蒸馏,馏出液用连续流动分析仪测定挥发酚含量。在4.96~200μg/L范围内,挥发酚的质量浓度与相对峰高线性相关,线性方程为y=235.31x+51.6,相关系数r~2=0.999 8,挥发酚的检出限为1.24μg/L。取2种土壤样品分别进行6次平行测定,测定结果的相对标准偏差分别为1.52%,1.56%。对2种挥发酚标准样品进行测试,相对误差分别为1.90%,2.08%,加标回收率在87.8%~95.5%之间。该方法适合大批量样品的连续分析,且无需使用三氯甲烷,与传统方法相比更安全环保。     

Flow fluorimetry of trace amounts of uranium(VI) after preconcentration on a tri-n-octylphosphine oxide/polyethylene column and elution with hydrogenphosphate solution

The fluorescence of uranyl ion is enhanced in phosphoric acid medium and in hydrogen-phosphate medium. The pH dependence of the fluorescence intensity showed maxima at pH 1–2 and pH 7–8. The concentration of phosphoric acid which gave maximum intensity was around 1 M, but in the hydrogenphosphate media an increase in the concentration lowered the intensity. The procedure was used in combination with preconcentration on a tri-n-octylphosphine oxide/polyethylene column. This simple system provided a limit of detection of 0.04 μg for uranium and the calibration graph was linear for the range 0.08–0.8 μg of uranium when 4–15 ml of sample solution was passed through the column. The flow fluorimetric method was applied to the determination of uranium in a spinel.     

Analytical applications of condensed phosphoric acid-I Determination of ferrous and total iron in iron ores after decomposition with condensed phosphoric acid

A simple method is described for the determination of ferrous and total iron in iron ores. Iron ores are dissolved by condensed phosphoric acid (CPA) very rapidly without any tedious and time-consuming manipulations such as elimination of silica and filtration. Under the proposed conditions (amount of sample 100 mg, amount of CPA added 10 g, heating temperature 290 degrees , heating time 30 min), magnetite, limonite and hematite are completely dissolved. The iron content can be determined in the presence of condensed phosphoric acid by titration with dichromate solution, if a slight modification is made. The total iron in iron ores, determined by the present method, is in agreement with that found by the JIS method. The ferrous iron in iron ores can be determined by dissolving the samples with CPA in a nitrogen atmosphere and titrating with dichromate solution. Chelatometric titration of iron after solvent extraction with MIBK from solutions prepared by use of CPA is found to be accurate for samples such as pyrite cinder. The ability of CPA to dissolve various materials has been investigated.     

湿法磷酸中钾、钠、钙、镁的原子吸收光谱法测定

在湿法磷酸生产过程中,为了对生产流程和产品质量进行控制,有必要对湿法磷酸中微量的钾、钠、钙、镁含量进行分析。用火焰原子吸收光谱法测定湿法磷酸中钾、钠、钙、镁受基体和背景以及溶液粘度的影响很大,特别是对钙含量的测定,干扰最严重[1]。为此本文提出用离子交换树脂分离     

电感耦合等离子体发射光谱法测定磷酸中的金属元素

建立了一种用电感耦合等离子体发射光谱仪(ICP-AES)测定磷酸中金属元素的分析方法。实验结果表明：选择合适的样品前处理方式和优化的仪器操作条件,方法的检出限可达到0.0012 ug/g~0.0552ug/g、加标回收率达到95%~105%,满足实际样品分析要求。