Xanthates are commonly used collectors in flotation processes but highly toxic to the aquatic environment. However, there few methods for reliable determination of low xanthate concentrations water samples. In this work, a sensitive, selective, and fast method is presented potassium ethyl (KEX). KEX was determined by high-performance liquid chromatography–inductively coupled plasma–mass spectro...

In this review we describe procedures, performance characteristics and limitations of methods available for the measurement of 25-hydroxyvitamin (25OHD) since the year 2000. The two main types of methods are competitive immunoassay and those based on chromatographic separation followed by non-immunological direct detection (HPLC, LC-MS/MS). Lack of a reference standard for 25OHD has, until rece...

Acylcarnitines are formed by esterification between fatty acids CoA or organic acids CoA molecules and carnitine. In various fatty acids oxidation defects and organic acidurias, there is increased concentration of corresponding acylcarnitines. Abnormalities in specific acylcarnitines are used in the diagnosis of fatty acids oxidation defects and organic acidurias. Most commonly used method for ...

BACKGROUND Reliable measurement of aldosterone with less interlaboratory variation than RIA would help standardize testing for primary aldosteronism. We set out to validate a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for aldosterone in human plasma. METHODS We prepared samples (EDTA plasma, lithium heparin plasma, and serum from separator and plain cl...

This study describes a multistage methodology to detect minute amounts of tetrodotoxin in fishes, plan that may be broadened include other marine organisms. was applied porcupinefish (Diodon hystrix) collected Punta Chiquirín, El Salvador. A three-stage approach along with post-acquisition processing employed, wit: (a) Sample screening by selected reaction monitoring (HPLC-MS/MS-SRM) analyses q...