共查询到20条相似文献,搜索用时 31 毫秒
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超高效亲水作用色谱-串联质谱法检测水中的苦味酸及苦氨酸 总被引:1,自引:0,他引:1
建立了一种超高效亲水作用色谱-串联质谱检测水中苦味酸及其降解产物苦氨酸的方法。采用Acquity UPLC BEH HILIC亲水作用色谱柱(100 mm×2.1 mm,1.7 μm,Waters)分离,用电喷雾电离串联质谱检测。地表水样品经过0.2 μm滤膜过滤之后即可直接进样,加标回收率达89%~107%;废水样品通过固相萃取(SPE)净化后进样分析,加标回收率达72%~101%。方法重复性的相对标准偏差为4.9%~14.7%。本方法对苦味酸和苦氨酸的检出限分别为0.1 μg/L和0.3 μg/L。此方法快速、准确,特异性强,灵敏度高,样品前处理方法简便易行,适用于地表水、废水样品的检测。 相似文献
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为解决GB/T 5750.11-2006生活饮用水标准检验方法中的3,3',5,5'-四甲基联苯胺(TMB)目视比色法检测余氯时出现的评价方法准确性欠佳、TMB显色剂发黄、显色体系偏绿等问题,对TMB目视比色法的评价方法、TMB显色剂的配制条件和水样的检测条件进行了研究。结果表明,次氯酸钠不宜作为余氯标准物质来评价TMB目视比色法的改进效果,而通过检测显色体系的A450和目视比色值相结合的方法来判断方法改进效果更为准确。采用优级纯浓盐酸和无氯纯水室温搅拌溶解,可使显色剂无色透明,从而解决TMB显色剂发黄的问题,符合国标要求。将显色剂配制用酸(盐酸)的浓度由国标中0.1mol/L变更为0.6 mol/L,可解决余氯显色体系偏绿的问题。显色体系pH变化后,显色时间、显色温度、显色剂用量可仍按照国标方法的要求进行操作。通过以上改进措施,进一步提高了余氯检测结果的准确度。 相似文献
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Avijit Pramanik Mouchumi Bhuyan Gopal Das 《Journal of photochemistry and photobiology. A, Chemistry》2008,197(2-3):149-155
The newly synthesized simple tripodal ligand tris-[2-(naphthalen-2-yloxy)-ethyl]-amine (L1) act as a fluorescence signaling system for aromatic guest. It forms inclusion complexes with several electron deficient aromatic compounds. This inclusion phenomenon has been studied by steady-state fluorescence spectroscopy and solid-state structural analysis. Electron-rich L1 shows dramatic color change and a concomitant quenching of luminescence in solution as well as solid phase when titrated with several other electron deficient aromatic guest molecules. Rather high selectivity towards the picric acid was observed. L1 simultaneously forms inclusion complex and organic salt co-crystal with the composition [(L1H+) (Pic−)] PicH (PicH = picric acid) when crystallized in the presence of picric acid. In the solid state, it forms a strong π–π, C–Hπ and C–HO type interactions. 相似文献
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An LC-MS method for the determination of picric acid (2,4,6-trinitrophenol), its reductive transformation products picramic acid (2-amino-4,6-dinitrophenol) and iso-picramic acid (4-amino-2,6-dinitrophenol) and hexyl (2,2',4,4',6,6'-hexanitrodiphenylamine) has been developed. The analytes were separated using ion-pairing chromatography with a volatile ion-pairing reagent suitable for subsequent MS detection. The performance of an atmospheric pressure chemical ionisation (APCI) and an electrospray ionisation (ESI) interface was compared. ESI-MS is more sensitive for the analytes, especially for hexyl and picric acid, APCI-MS delivered more fragments necessary for unequivocal identification. With LC-ESI-MS limits of detection using single ion monitoring (SIM) mode are 4 ng (iso-picramic acid), 800 pg (picramic acid), 400 pg (picric acid) and 80 pg (hexyl). For quantification, 15N-picric acid was used as an internal standard. Using this new method, the degradation of picric acid in soil was monitored in a laboratory study. Furthermore, the presence of picramic acid was for the first time verified in soil samples from a former ammunition plant. 相似文献
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Wang Xiaolin Liu Yinong Fu Yibei 《Journal of Radioanalytical and Nuclear Chemistry》1995,189(1):127-132
The extraction behavior of rubidium with a crown ether has been studied and methods for the separation and determination of rubidium have been developed. Rubidium was separated with tetraphenylborate from sample solution, and then quantitatively extracted into nitrobenzene by 18-crown-6 from 0.05 mol/l picric acid (pH 6) and back-extracted by 6 mol/l hydrochloric acid. Rubidium was determined by the neutron activation method in rock samples. 相似文献
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The microgram detection of phenols and determination of nitro- and nitroso-phenols is based on their treatment in alkaline solution with a chlorinated hypochlorite solution, resulting in characteristic colours. Ion-exchange resin beads are used to make the test sensitive and selective. A few nitro and nitroso compounds have been determined spectrophotometrically. 相似文献
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利用荧光能量转移设计高灵敏苦味酸光极膜 总被引:1,自引:0,他引:1
利用荧光能量转移设计高灵敏苦味酸光极膜王柯敏,曾恚恚,俞汝勤(湖南大学化学化工系,长沙,410082)关键词荧光能量转移,光极,苦味酸基于稠环芳烃荧光熄灭的苦味酸光极膜[1a,2]在选择性方面优于传统苦味酸根离子电极,较适于实际应用,但在检测低浓度苦... 相似文献
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以玛卡为碳源,采用水热法制备荧光碳点。碳点水溶液在激发波长为315 nm时,最大荧光发射波长为425 nm。在玛卡荧光碳点的磷酸盐缓冲液(0.2 mol/L,pH 5.8)中,加入苦味酸,其荧光被猝灭,基于此建立了以玛卡荧光碳点为荧光探针测定苦味酸的方法。本方法检测苦味酸的线性范围为0.4~80 mmol/L,相关系数为0.9978,检出限为110 nmol/L(S/N=3),本方法线性范围宽、灵敏度高、响应快(2 min内),选择性和抗干扰能力良好。用于实际水样中苦味酸的检测,加标回收率为92.0%~110.0%,结果令人满意。 相似文献
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K.G. Blass 《Microchemical Journal》1984,30(2):147-153
The present study has confirmed the formation of picramic acid and methylguanidine during the heated Jaffe' reaction. Picramic acid was isolated on thin-layer chromatography from 0.5:1 and 1:1 heated creatinine:picric acid molar ratio test solutions, but not for similarly performed 3:1 test solutions. A Dowex column was employed to isolate methylguanidine from 0.5:1 and 3:1 molar ratio test solutions. Methylguanidine was similarly isolated from a heated alkaline creatinine solution. 相似文献
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El-Mossalamy EH 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(5):1161-1167
The molecular charge-transfer complexes of phenylephrine with picric acid and m-dinitrobenzene have been studied and investigated by IR, 1H NMR electronic spectra in organic solvents and buffer solutions, respectively. Simple and selective methods are proposed for the determination of phenylephrine hydrochloride in bulk form and in tablets. The two methods are based on the formation of charge-transfer complexes between drug base as a n-donor (D) and picric acid, m-dinitrobenzene as pi-acceptor (A). The products exhibit absorption maxima at 497 and 560 nm in acetonitrile for picric acid and m-dinitrobenzene, respectively. The coloured product exhibits an absorption maximum at 650 nm in dioxane. The sensitive kinetic methods for the determination phynylephrine hydrochloride are described. The method is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permanganate at room temperature for a fixed time at 20 min. 相似文献
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The liquid membrane oscillation of a novel water (aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution)/oil (picric acid in chloroform solution)/water (aqueous glucose solution) system was investigated. By using homemade device, the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid, types of alcohol and other organic solvents at different temperature were measured. The results show that the water (aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution)/oil (0.5 mmol/L of picric acid in chloroform solution)/water (aqueous glucose solution) system performed sustained and stable oscillation at 30 ℃. And the novel system can recognise added amino acid. 相似文献
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Triphenylamine based, dumbbell shaped, highly fluorescent compound 1 was designed and synthesized. Compound 1 showed blue emission with quantum efficiency as high as 0.78 in benzene solution. Compound 1 showed turn-off sensitivity to picric acid, which is a common constituent of many powerful explosives and unavoidable environmental threats. The turn-off sensitivity to picric acid is attributed to the excited state charge transfer from compound 1 to picric acid. Compound 1 selectively senses picric acid with a detection limit of ∼400 ppb. 相似文献
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A method has been developed for determining the chloride anion with silver nitrate in presence of the hypochlorite, chlorite and chlorate anions.The chlorate anion does not interfere with the determination. In the presence of chlorite anions the figures for Cl' are too low in acid media.The hypochlorite anion should be reduced to the Cl' anion by PENOT'S solution. 相似文献
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Md Mustafizur Rahman Kaoru Fujinaga Yasushi Seike Minoru Okumura 《Analytical sciences》2004,20(1):165-170
A simple in situ visual and tristimulus colorimetric method for the determination of trace arsenic in environmental water after collecting arsenic on a test paper impregnated with mercury(II) bromide and rosaniline chloride by its reduction aeration has been developed. The color development on the test paper is based on the formations of AsH(HgBr)2 (yellow) and/or As(HgBr)3 (brownish yellow) by a reaction between mercury(II) bromide and arsine (AsH3), which is produced through the reduction of As(III) (arsenite ion) and/or As(V) (arsenate ion) in a sample solution. To a sample solution, potassium iodide, tin(II) chloride, zinc sand and 4 ml of 6 M hydrochloric acid solution were added successively. The liberated arsine was collected on the test paper. The yellow or brownish-yellow color intensity on the test paper was measured by a tristimulus colorimeter and also by a visual method. The established method is applicable to the determination of arsenic in environmental water sample such as river, brackish, and seawater types. 相似文献
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In neutral medium, picric acid (PA) reacts with chlorpromazine (CPM) hydrochloride with the formation of an orange compound, sparingly soluble in water, of molar ratio PA:CPM = 1:1. The compound is thermally stable up to a temperature of about 200 degrees C. The m.p. (178 degrees C) can be used for identification of picric acid as well as of chlorpromazine hydrochloride. Chlorpromazine picrate is extracted quantitatively with benzene, and the extract can be used for colorimetric determination of chlorpromazine hydrochloride. Beer's law is obeyed in the CPM concentration range 10-60 mug/ml. 相似文献
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In this article, we report a colorimetric approach for the determination of hypochlorite (OCl(-)) with gold nanoparticles (Au NPs). The test proceeds as two individual steps and selectivity is developed based on the strong oxidizing ability of hypochlorite. In concentrated phosphate buffer (PB), the red solution of citrate-capped Au NPs could be stabilized by the chemisorption of 11-mercaptoundecanoic acid (MUA), without which the colloidal suspension turned blue because of salt-induced particles aggregation. However, by its oxidizing power, OCl(-) converted the alkanethiol to a sulfonate derivative, which could not protect Au NPs from aggregation, thereby a blue solution was observed after the subsequent addition of Au suspension. With this method and under the optimal conditions (28 nm Au NP, 50 mM PB, pH 7.0, and 10 min for the colorimetric response), 1.5 μM of OCl(-) can be easily visualized by the naked eye. This sensitive and selective colorimetric assay opens up a fresh insight of facile, rapid, and reliable detection of OCl(-), and may find its future application in the monitoring of OCl(-)/HOCl in waters sanitized by chlorine or hypochlorite compounds. 相似文献
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