Experimental investigation of the polymer melt flow during injection post‐filling process

Cheng, Nien-Tien; Chen, Y. C.; Chen, S. C.

doi:10.1002/aic.690411217

Cited by 2 publications

(2 citation statements)

References 10 publications

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“…The primary investigation has suggested that oxalic acid is most likely to be produced in the oxidation of pHPP by dissolved oxygen in alkaline solution, This conclusion is based on the fact that oxidation of pHPP by dissolved oxygen yielded a compound that would greatly enhance the ECL of Ru(byp) 3 2+ just as authentic oxalic acid did. However, besides oxalic acid, many other compounds such as amines, amino acids, and alcohols have been reported to have ECL activity in the Ru(byp) 3 2+ ECL system, and all probably interfere with the detection of oxalic acid. So in this paper, a new CE-ECL separation and detection system was developed and used for the qualitative analysis of an oxidation degradation solution of pHPP.…”

Section: Resultsmentioning

confidence: 99%

Chemical Oxidation of p-Hydroxyphenylpyruvic Acid in Aqueous Solution by Capillary Electrophoresis with an Electrochemiluminescence Detection System

Chen

Chi

et al. 2003

Anal. Chem.

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A system of capillary electrophoresis with electrochemiluminescence detection (CE-ECL) together with UV spectroscopic and electrochemical methods were used to study the chemical oxidation of p-hydroxyphenylpyruvic acid (pHPP) by dissolved oxygen in aqueous solution. The pHPP was observed to be readily oxidized by dissolved oxygen in alkaline solution and yielded a compound that strongly enhanced the electrochemiluminescence of Ru(bpy)23+. This compound was separated and detected by a new CE-ECL system and revealed to be oxalate by being compared with an authentic sample of oxalate. The chemical oxidation mechanism of pHPP by dissolved oxygen was discussed in this paper.

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Section: Resultsmentioning

confidence: 99%

Chemical Oxidation of p-Hydroxyphenylpyruvic Acid in Aqueous Solution by Capillary Electrophoresis with an Electrochemiluminescence Detection System

Chen

Chi

et al. 2003

Anal. Chem.

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“…18) We also reported the detection of primary amines using a cycloaddition reaction of the amines with divinylsulfone (DVS). 20) In contrast, the chemiluminescence procedure using Ru(bpy) 3 2ϩ has become an attractive method with HPLC for the detection of underivatized 15,[21][22][23][24] and derivatized amino acids, 25,26) due to low detection limits, wide linear dynamic range and relatively simple instrumentation. Though we previously reported the determination of tryptophan in human plasma using the Ru(bpy) 3 2ϩ -indole system, 15) the Ru(bpy) 3 2ϩ ECL method has not been applied to the determination of amino acids in human plasma samples.…”

mentioning

confidence: 99%

Determination of Aromatic and Branched-Chain Amino Acids in Plasma by HPLC with Electrogenerated Ru(bpy)33+ Chemiluminescence Detection

Uchikura

2003

CHEMICAL & PHARMACEUTICAL BULLETIN

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Several types of inborn errors are known in the metabolism of aromatic amino acids phenylalanine (Phe), tyrosine (Tyr) and tryptophan (Trp), the branched-chain amino acids valine (Val), leucine (Leu), and isoleucine (Ile), and the sulfur-containing amino acid methionine (Met), and these can cause phenylketonuria (PKU), tyrosinemia, tetrahydrobiopterin deficiency and hypermethioninemia. The determination of Phe, Tyr, Trp, Val, Leu, Ile and Met levels is important in the diagnosis of these inborn metabolism disorders. PKU is one of the disorders most widely screened for newborn babies.1,2) Several techniques such as the Guthrie test, 3) the microplate fluorimetric system, 2) HPLC with fluorescence 4) and mass spectrometry (MS), 5) capillary electrophoresis 6) and enzymatic assay 7) have been used to screen PKU in newborn blood.A variety of pre-and post-column derivatization HPLC techniques have been developed for the determination of amino acids. 8) dansylchloride 9) and 4-(dimethylamino)-azobenzene-4Ј-sulfonyl chloride, 10) all of which form UV absorbent or fluorescent species with amino acids. All of these, however, suffer from one or more of the following disadvantages: lack of quantitative reaction with certain amino acids, complex coupling precedure or instability of the products or reagent.On the other hand, a few chemiluminescence HPLC methods have been reported for the determination of amino acids.11,12) Kobayashi and Imai 12) reported HPLC separation of dansyl amino acid derivatives combined with peroxyoxalate chemiluminescence detection. Detection limits reported were at the several fmol levels. However, the bis(2,4,6-trischlorophenyl) oxalate system is itself unstable. Recently, a selective and sensitive tris(bipyridine)ruthenium(II) (Ru(bpy) 3 2ϩ ) electrogenerated chemiluminescence (ECL) system has been applied for the detection or determination of oxalate with HPLC 13) or flow injection analysis (FIA), 14) indoles with HPLC 15) or FIA, 16) and tertiary amines with HPLC 17) or FIA. 18) We previously reported that alicyclic tertiary amines can be detected at the pmol level using this FIA system.19) The ECL intensities of aliphatic primary amines were very low compared with those of the tertiary amines; they could only be detected at levels about 1000-times lower than those of tertiary amines.18) We also reported the detection of primary amines using a cycloaddition reaction of the amines with divinylsulfone (DVS). 20) In contrast, the chemiluminescence procedure using Ru(bpy) 3 2ϩ has become an attractive method with HPLC for the detection of underivatized 15,[21][22][23][24] and derivatized amino acids, 25,26) due to low detection limits, wide linear dynamic range and relatively simple instrumentation. Though we previously reported the determination of tryptophan in human plasma using the Ru(bpy) 3 2ϩ -indole system, 15) the Ru(bpy) 3 2ϩ ECL method has not been applied to the determination of amino acids in human plasma samples.In this paper, we describe the HPLC separation of aromatic and branched-ch...

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Experimental investigation of the polymer melt flow during injection post‐filling process

Cited by 2 publications

References 10 publications

Chemical Oxidation of p-Hydroxyphenylpyruvic Acid in Aqueous Solution by Capillary Electrophoresis with an Electrochemiluminescence Detection System

Chemical Oxidation of p-Hydroxyphenylpyruvic Acid in Aqueous Solution by Capillary Electrophoresis with an Electrochemiluminescence Detection System

Determination of Aromatic and Branched-Chain Amino Acids in Plasma by HPLC with Electrogenerated Ru(bpy)33+ Chemiluminescence Detection

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