Quantification of the Pyrrolizidine Alkaloid Jacobine inCrassocephalum crepidioidesby Cation Exchange High-Performance Liquid Chromatography

2017 ◽  
Vol 29 (1) ◽  
pp. 48-58 ◽  
Author(s):  
Wilfried Rozhon ◽  
Lukas Kammermeier ◽  
Sebastian Schramm ◽  
Nayeem Towfique ◽  
N. Adebimpe Adedeji ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Cation Exchange ◽  
High Performance ◽  
Pyrrolizidine Alkaloid

Catecholamine measurements by high-performance liquid chromatography

1984 ◽  
Vol 247 (1) ◽  
pp. E13-E20 ◽  
Author(s):  
P. Hjemdahl
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Cation Exchange ◽  
High Performance ◽  
Reversed Phase ◽  
Exchange Chromatography ◽  
Lower Sensitivity ◽  
Tissue Samples ◽  
Basal Plasma ◽  
Postcolumn Derivatization

The development of sensitive detectors has allowed the use of high-performance liquid chromatography (HPLC) for measurements of catecholamines in extracts of plasma, urine, and tissue samples. Separation of the catecholamines may be effected by reversed phase chromatography or cation-exchange chromatography and quantitation by electrochemical detection (EC) or by fluorometry coupled with postcolumn derivatization according to the trihydroxyindole (THI) method. EC has a somewhat lower sensitivity than the THI method for norepinephrine (NE) and epinephrine (E). The THI method is insensitive to dopamine (DA). Basal plasma E levels of 0.1 nM (20 pg/ml) or less may be measured in sample volumes of 1-2 ml with EC. Sensitivity and reproducibility of an assay is not necessarily a guarantee of accuracy. It is argued that new methods and modifications of old methods should be validated against accepted methodology. This is rarely the case. Cation exchange HPLC with EC has been adequately validated, but only one of the reversed phase methods has been compared with radioenzymatic methodology. HPLC has the advantages of economy, speed, and more stimulating laboratory work, as compared with radioenzymatic methodology.

Usefulness of Cation Exchange High Performance Liquid Chromatography as a Testing Procedure

PEDIATRICS ◽  
1989 ◽  
Vol 83 (5) ◽  
pp. 849-851
Author(s):  
Titus H. J. Huisman
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Cation Exchange ◽  
Cellulose Acetate ◽  
Isoelectric Focusing ◽  
High Performance ◽  
Testing Procedure ◽  
Cellulose Acetate Electrophoresis ◽  
Blood Samples ◽  
Testing Procedures

Testing of cord blood or newborn blood samples for hemoglobin abnormalities should include clinically important hemoglobinopathies other than sickle cell anemia (SS), such as SC, SD, SO, S-β- thalassemia (thal), EE, SE, and α-thal, and should place the quality of the testing procedures (ie, accuracy of diagnosis) above quantity (ie, number of samples tested over a given period). There is no single method available that is suitable for the identification of each of the numerous abnormalities; thus, at least two, and often more than two, procedures must be used to reach a definitive diagnosis. For this reason, blood samples collected in vacutainers with ethylenediaminetetraacetic acid as anticoagulant are preferred to those collected on filter papers. The latter approach also has the disadvantage that, under a less than optimal transport system, hemoglobin is readily modified (oxidation, glycosylation, protein-protein interaction), producting extra bands or peaks in electrophoretic or chromatographic separations that interfere with an appropriate identification of various genetically determined hemoglobin variants. In our laboratories, in which hemoglobin identification has been routine for more than 25 years, we consider the following procedures acceptable primary testing methods: starch gel electrophoresis at pH 8.9, cellulose acetate electrophoresis at pH 8.5 to 8.9, isoelectric focusing, and fast cation exchange high performance liquid chromatography (HPLC). The following five methods are excellent confirmatory testing procedures: citrate agar electrophoresis at pH 6.1, cation or anion exchange macrochromatography, isoelectric focusing, cation exchange HPLC, and immunologic procedures. Combinations of these techniques will often lead to acceptable data, and the general approach followed in our institute is given in Fig 1. Cellulose acetate electrophoresis at alkaline pH is still the primary testing procedure, and citrate agar electrophoresis at pH 6.1 and micro-HPLC procedures are the main confirmatory methods.

scholarly journals Two familial cases of Hb Tyne confirm instability as cause of low expression

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Beverley M. Pullon ◽  
Stephen O. Brennan
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Cation Exchange ◽  
High Performance ◽  
Blood Count ◽  
Full Blood Count ◽  
Familial Cases ◽  
First Case ◽  
Β Chain ◽  
Low Expression

We report a second occurrence of hemoglobin (Hb) Tyne, [β5 (A2) Pro>Ser] HBB:c.16C>T(p.Pro6Ser), which like the first case was associated with normal hematology. We verified the variant was mildly unstable by showing it was greatly enriched in isopropanol precipitates. This minor instability accounts for the slightly decreased expression of the new β chain. The variant was picked up as an interfering component on HbA1c testing using cation exchange high performance liquid chromatography (HPLC). However, this may be an advantage in detecting electrophoretically silent variants. Furthermore, this report also highlights the importance of uneven or sloping baselines on HPLC, which could reflect the presence of a variant hemoglobin even in the presence of normal electrophoresis and full blood count. 我们报告了第二例血红蛋白(Hb) Tyne [β5 (A2) Pro>Ser] HBB:c.16C>T(p.Pro6Ser)的出现，其与第一例一样伴随血象正常。我们通过将该变体在异丙醇沉淀物中的显著富集证实了其有轻度不稳定性。这种微小的不稳定性可用来说明新β链表达的轻微下降。该变体在使用阳离子交换高效液相色谱（HPLC）的HbA1c检测中作为干扰成分检出。然而，在检测电泳沉默变体方面这可能使一个优势。此外，本报告还强调了不平或倾斜的基线对HPLC的重要性，这会反映出血红蛋白变异体的存在，即使电泳和全血计数正常。

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