Uporaba in kalibracija pH metra v reguliranih pogojih

KOZOLE, DAMJAN (author), Pušnik, Igor (mentor)

Vrednost pH je pomembna veličina pri proizvodnem procesu. V diplomskem delu je predstavljen proces delovanja pH metra in njegove karakteristike. Kalibracija oz. umerjanje pH metra je pomemben del vsakega proizvodnega procesa pri proizvodnji produkta v farmaciji in v ostalih panogah, kjer se držijo strogih pogojev dela in delujejo v reguliranih pogojih. Problem, ki ga imamo pri merjenju pH vrednosti je, da nismo prepričani ali so naše meritve točne. Zato v diplomskem delu opišem karakteristike pH sond, s katerimi si lahko pomagamo in lažje prepoznamo napake. Cilj diplomskega dela je bil, da izboljšam proces umerjanja pH metrov in merjenje pH vrednosti s stališča točnosti in negotovosti. To dosežem s pomočjo avtomatizacije meritev in sicer tako, da pH meter povežem na SCADA sistem, s pomočjo katerega se meritve sproti shranjujejo in se na zaslonu tudi prikazuje trend izmerjenih vrednosti. V uvodu diplomskega dela na kratko predstavim kaj so biološka zdravila. Predstavim regulatorni organ FDA in njegovo pomembno poslanstvo zaščite bolnikov in kakovostno uvrščanje zdravil na trg. V nadaljevanju opišem, kako se v vsakem farmacevtskem podjetju držijo smernic GMP. Pomembno je razumevanje samega proizvodnega procesa, ki deluje v takem okolju. Sledi poglavje o kalibraciji pH metra, kar je ključna tema diplomske naloge. Tekom študija smo spoznali pomembne pojme kot so: točnost, natančnost, kalibracija, itd. Vsi ti pojmi so jasno opisani, saj so pomembni za razumevanje. V nadaljevanju opišem, zakaj potrebujemo kalibracijo inštrumenta in kakšne načine poznamo. Predstavim dejavnike, ki vplivajo na kakovost meritev s pH metrom. V naslednjem poglavju predstavim kalibracijo generičnih pH sond ter opišem kaj so puferske raztopine oz. pufri. Pri pufrih predstavim pomen sledljivosti. V zaključku dela opišem delovanje Hamiltonovega pH senzorja. Uporaba Hamiltonovega pH senzorja preko dlančnika Handheld prinaša določene pomanjkljivosti. Vse prehitro se nam izprazni naprava Handheld, ker kalibracija poteka s pomočjo wi-fi signala. Prav tako je težava tudi v sledljivosti podatkov ter neodzivnosti naprave. Kalibracija in meritve pH metra preko SCADA sistema nam omogoča boljši in hitrejši proces kalibracije in meritev pH vrednosti. Podatke lahko statistično obdelamo in tako s pomočjo statističnih operacij izboljšamo naš proces. V primeru uporabe sistema SCADA je zagotovljena tudi sledljivost podatkov. V zaključku predstavim potek kalibracije preko SCADA sistema in dlančnika Hamilton. Meritve ne potekajo več samo preko dlančnika, ampak imamo nadzorovan proces preko SCADE. Na SCADA sistemu se meritve zapišejo na interval desetih minut. Te podatke lahko uporabimo za statistično obdelavo. V zaključku izračunamo standardno deviacijo meritev. S pomočjo standardne deviacije določimo negotovost. Na grafih predstavim porazdelitve, ki nam povejo, če so meritve točne in natančne. Na koncu še predstavim prispevke negotovosti pri kalibraciji pH metrov.

• Language: Slovenian
• Keywords: regulirano okolje, pH meter, pH Hamilton, proizvodnja, kalibracija, točnost, negotovost, sledljivost
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2016
• PID: 20.500.12556/RUL-88453
• Publication date in RUL: 06.01.2017

Secondary language

• Language: English
• Title: Use and calibration of the pH meter in controlled conditions

Abstract

The pH value is an important variable in the production process. This bachelor's thesis presents the process of the functioning of the pH meter and its characteristics. Calibrating the pH meter is an important part of every production process when producing a product in the pharmaceutical and other industries which adhere to strict working conditions and work in a regulated environment. The problem we face when measuring pH values is not being sure if our measurements are accurate. That is why in the thesis I describe the characteristics of pH probes which can be used to aid us and make recognising errors easier. The objective of the thesis is to improve on the process of calibrating pH meters and measuring pH values from the point of view of accuracy and uncertainty. I achieve this by automating measurements by connecting the pH meter to the SCADA system with which the measurements are stored continuously and the display shows the trends of measured values. In the introduction to the thesis I briefly introduce biological medicinal products. I introduce the regulatory authority FDA and its important mission of protecting the patients and high-quality introduction of medicines to the market. Afterwards I describe how every pharmaceutical company follows GMP guidelines. The understanding of the production process operating in such an environment itself is important. This is followed by the chapter on calibrating the pH meter, which is the main theme of the thesis. During our studies we learned important terms such as: accuracy, precision, calibration, etc. All these terms are clearly described as they are important for understanding. I continue to describe why we need to calibrate the instrument and the known ways of doing so. I introduce the factors which influence the quality of measurements made with a pH meter. In the next chapter I introduce the calibration of generic pH probes and describe buffer solutions or buffers, respectively. I introduce the importance of the traceability of buffers. In the conclusion of the thesis I describe the functioning of Hamilton's pH sensor. The use of Hamilton's pH sensor through a Handheld PDA has certain shortcomings. The Handheld device runs out of battery all too quickly because the calibration is carried out with the help of a Wi-Fi signal. The traceability of data and unresponsiveness of the device are also problematic. The calibration and measurements of the pH meter using the SCADA system provide us with a better and faster process of calibration and measuring pH values. The data can be statistically analysed and used to improve on our process with the help of statistic operations. When using the SCADA system, the traceability of data is also ensured. In the conclusion of the thesis I introduce the process of calibration with the SCADA system and the Hamilton PDA. The measurements do not only take place via the PDA, we also have a controlled process via SCADA. On the SCADA system, the measurements are entered at intervals of ten minutes. This data can be used for statistical processing. In the conclusion we calculate the standard deviations of the measurements. With the help of the standard deviation we determine uncertainty. I introduce the distributions which tell us if the measurements are accurate and precise using charts. Finally I introduce the contributions of uncertainty when calibrating pH meters.

• Keywords: regulated environment, pH meter, pH Hamilton, production, calibration, accuracy, uncertainty, traceability