Use of modifiers in electrothermal solid sampling

The concept of chemical modification (CM) is extremely popular in modern elec-trothermal-assisted atomic techniques. As per lUPAC s recommendations [47], in order to influence processes taking place in the atomizer in the desired way, reagents called chemical modifiers may be added. These can help to retain the analyte to higher temperatures during pyrolysis, remove unwanted concomitants or improve atomization in other ways . However, there is a tendency towards broadening the scope of this term, starting from the classical and still used term matrix modifier , matrix/analyte modifier or instrumental matrix modification to indicate the useful effects of the type, pressure and flow-rate of protective gas or gas mixtures internal matrix modifier for matrix constituent s) with favourable effects on processes in the atomizer, either by themselves (e.g. refractory components) or upon addition of suitable promoters permanent modifiers for 

Existing chemical modifiers span all aggregation states and a wide variety of chemical families, namely  

Inorganic salts — the most popular group — the modifiers being both cations such as Pd(ll), Ni(Il) or NH4, and anions such as nitrate, phosphate, vanadate or tungstate. Nitrate and ammonium ions, respectively, have proved the best counterions for these salts. 

Organoelements and complexed forms of modifiers, which are useful when samples or analytes are transferred into organic phases such as extracts, leachates, oils, fats, petroleum products, organometal [lead acetate or acetylaeetonate] solutions, etc. Inorganic acids (HNO H3PO4) and bases (aqueous ammonia). 

Organic acids (acetic, tartaric) and bases (e.g. solvents for biological tissues including TMAH, TAAH and thyamine hydroxide). 

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