Analytical derivatizations in environmental analysis.

Analytical derivatization is a technique that alters the structure of an analyte and produces a product more suitable for analysis. While this process can be time-consuming and add reagents to the procedure, it can also facilitate the isolation of the analyte(s), enhance analytes' stability, improve separation and sensitivity, and reduce matrix interferences. Since derivatization is a functional group analysis, it improves selectivity by separating reactive from neutral compounds during sample preparation.

Solid phase analytical derivatization as a sample preparation method.

Analytical derivatization (AD) is an important procedure in analysis as it improves the sensitivity, selectivity and chromatographic separation. Solid phase analytical derivatization (SPAD) combines extraction and derivatization into a single step fulfilling many aspects of a good sample preparation technique, which includes low organic solvent consumption, economical, ease of automation with any chromatographic system and applicability in a wide range of complicated matrices. In this review we have focused on wide applications of SPAD when used in combination with different sample preparation methods, such as solid phase extraction, ion exchange resins, solid phase microextraction, in-tube, microfluidic devices, and hollow fiber extraction methods.

Solid phase analytical derivatization of anthropogenic and natural phenolic estrogen mimics with pentafluoropyridine for gas chromatography-mass spectrometry.

A simple, low cost, fast and sensitive method is reported for the determination of the four endocrine disrupting chemicals (EDCs) 4-tert-butylphenol, 4-tert-octylphenol, bisphenol A and 17β-estradiol using pentafluoropyridine as the derivatizing reagent. These EDCs were determined by simultaneous extraction and derivatization in a solid phase analytical derivatization (SPAD) technique without the aid of any phase transfer catalyst (PTC) or an ion-pair mechanism. Recoveries of analytes as their tetrafluoropyridyl derivatives from water ranged from 71% for 4-tert-butylphenol to 106% for 17β-estradiol; from urine they ranged from 61% for 17β-estradiol to 91% for 4-tert-octylphenol; and from humic acids solution the ranged from 59% for 17β-estradiol to 104% for 4-tert-octylphenol in humic acid solutions.

A cost efficiency comparison between the multiple mini-interview and traditional admissions interviews.

A major expense for most professional training programs, both financially and in terms of human resources, is the interview process used to make admissions decisions. Still, most programs view this as a necessary cost given that the personal interview provides an opportunity to recruit potential candidates, showing them what the program has to offer, and to try and gather more information about the candidates to ensure that those selected live up to the espoused values of the institution. We now have five years worth of experience with a Multiple Mini-Interview (MMI) process that, unlike traditional panel interviews, uses the OSCE model to have candidates interact with a larger number of interviewers.