Določevanje bora v tekočih in trdnih vzorcih s pomočjo masne spektrometrije z vzbujanjem v induktivno sklopljeni plazmi

Kumer, Veronika (author), Perdih, Franc (mentor)

Bor, običajno podan kot borov oksid (B2O3), je ena izmed sestavin borosilikatnega stekla, ki je pomembna komponenta v proizvodnji steklene volne. Ker so surovine, ki vsebujejo bor, zelo drage, se bor vzdržuje na točno določeni koncentraciji, ki se jo preverja s titracijsko metodo. Titracija je časovno zelo potraten proces in je primerna le za vzorce, ki vsebujejo več kot 0.35 masnih odstotkov B2O3. Bolj optimalna rešitev je meritev z masnim spektrometrom z induktivno sklopljeno plazmo (ICP-MS), saj je priprava vzorcev enostavnejša, analizira se lahko več vzorcev hkrati, s tem pa se tudi zmanjša možnost napak in prihrani veliko časa. Ključna komponenta ICP-MS-a je stabilna argonova plazma, ki pri zelo visoki temperaturi molekule razbije na posamezne ione, le - ti pa potujejo naprej skozi kvadrupol in se ločijo na osnovi razmerja med maso in nabojem (m/z). Zaradi občutljivosti naprave, se ICP-MS uporablja predvsem za analizo elementov v sledovih, zato je ta analizna tehnika primerna za določevanje bora v naših vzorcih. V diplomskem delu smo optimizirali obstoječo metodo za določitev koncentracije bora v stekleni ter kameni volni s pomočjo ICP-MS. Rezultate realnih vzorcev smo primerjali s koncentracijami bora v standardnih referenčnih materialih. Rezultati meritev bora so pokazali, da z obstoječo metodo pri stokratni redčitvi vzorca zelo dobro merimo višje koncentracije bora (nad 0.35%) v vzorcih in bi lahko v tem primeru ICP-MS analizo uporabljali namesto časovno zamudne titracije. ICP-MS je primeren tudi za merjenje vzorcev z nizko koncentracijo bora (pod 0.35%). Poleg metode ICP-MS, ki se uporablja za analizo tekočih vzorcev, smo uporabili tudi metodo laserske ablacije, sklopljene z metodo ICP-MS. Vzorci pri tej analizni tehniki so v trdnem stanju, pripravljeni pri dveh različnih temperaturah, in sicer pri 750 ° in 1150 °C. Rezultati so pokazali, da LA-ICP-MS lahko nadomesti tekočinsko ICP-MS pri vzorcih z visoko koncentracijo bora, saj so bile relativne razlike med rezultati, pridobljenimi v internem laboratoriju in rezultati, pridobljenimi na zunanjem inštitutu majhne (do 3.4%).

• Language: Slovenian
• Keywords: bor, masna spektrometrija, induktivna sklopljena plazma, laserska ablacija
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-125534
• COBISS.SI-ID: 56968195
• Publication date in RUL: 23.03.2021

Secondary language

• Language: English
• Title: Boron Determination in Liquid and Solid Samples by Inductively Coupled Plasma - Mass Spectrometry

Abstract

Boron oxide (B2O3) is one of the components of borosilicate glass, which is used as an important raw material in the production of glass mineral wool. Raw materials containing boron are very expensive and this is one of the main reasons that the concentration of boron is maintained at a certain level. For boron determination usually the titration method is used. Since this is a very time-consuming procedure and has high boron detection limit (0.35%), determination of boron by using the inductively coupled plasma-mass spectrometry (ICP-MS) would be a better solution. Furthermore, sample preparation for ICP-MS measurements is easier and more samples can be analysed at the same time. Stable argon plasma is a key component of the ICP-MS. At very high temperatures molecules are ionised. Ions are traveling through quadrupole and are separated according to their mass and charge (m/z) ratio. Due to its high sensitivity, the ICP-MS is mainly used for trace analyses and is appropriate technique for boron determination in our samples. In the diploma thesis, the existing ICP-MS method for boron determination in glass and rock mineral wool was optimised. The results of real samples were compared with boron concentrations in standard reference materials. The results showed that high concentrations of boron (above 0.35%) could be accurately determined by current method and 100-fold dilution of the sample. It can be concluded that the solution mode ICP-MS can be used instead of time-consuming titration. In addition, with that method also concentrations below 0.35% can be determined. Beside the solution mode ICP-MS, laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used. Solid state samples were prepared at two different temperatures, 750 °C and 1150 °C. The results showed that LA-ICP-MS can replace the solution mode ICP-MS when boron concentrations are high, since the relative differences between the results obtained in the internal laboratory compared to the results obtained in the external laboratory were low (up to 3.4%).

• Keywords: boron, mass spectrometry, inductively coupled plasma, laser ablation