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1 Application field / Industry branch: Chemistry / Polymer Industry Electronics Energy Nutrition / Agriculture Geology / Mining Semiconductor Technology Clinical Chemistry / Medicine / Sanitation / Health Care Cosmetics Material Analysis Metallurgy / Electroplating Pharmacy Refineries / Petrochemistry Environment / Water / Waste Other

2 Short Application HR-CS SS GF MAS Sample Matrix Other ingredients of the tablet besides sodium fluoride are sorbitol, xylitol, Mg stearate, talcum and polyvinylpyrrolidone. Experimental Sample preparation One tablet to be examined was ground by the customer and made available for analysis. The powder was used without further sample preparation directly for analysis with the solid AA technique. The results of the fluorine content from the direct solids analysis are to be verified with HR-CS AAS for liquid samples. For this, approx g of the powder was dissolved in 50 ml of DI water. The sample could not be completely dissolved. A suspension was formed and a precipitate when left standing for a period of time. Therefore, in order to detect the total fluorine content, the suspension was shaken both prior to dilution with DI water and prior to analytical measurement as a means of achieving homogenization. Determination The measurements were carried out using the contraa High-Resolution Continuum Source AAS for graphite furnace technology and the solid sampler SSA 600L equipped with a liquid dosing unit. For the determination of fluorine in the suspension, the liquid sampler MPE 60 was used. For the direct solid determination, a solid sampling graphite tube was used. For the analysis of the suspension, a pyrolytically coated platform tube with integrated PIN platform was used. The fluorine concentration was determined via the molecular absorption of gallium mono-fluoride. To form GaF, 10 g/l of gallium (III) nitrate hydrate (Sigma-Aldrich) in water was used as the molecule formation reagent. The graphite sample carriers for the direct solid AAS or the PIN platforms in liquid mode were permanently coated with Zr (1 g/l Zr) prior to analytical use. To stabilize the fluorine analyte and the Ga molecule formation reagent during drying and pyrolysis, a Pd/Mg/Zr modifier (0.1 %/0.05 %/20 mg/l Pd/Mg/Zr) and a 10 g/l Na acetate modifier were used. The Pd/Mg/Zr modifier was pretreated thermally at 1200 C with the major part of the Ga(NO 3 ) 3 molecule formation reagent in order to activate the Pd. Under these conditions, a pyrolysis temperature for the samples of 600 C and a molecule formation temperature of 1600 C were used. Since the sample has a relatively high fluorine concentration in the ppm range, the most sensitive molecular absorption line

3 of GaF was not used. The wavelength of nm enables a calibration of fluorine in the concentration range of ppm F in the solid for a sample weight of approx. 0,1 0,5 mg. Method parameters Wavelength [nm] T Pyr. [ C] T Atom. [ C] Ramp [ C/s] Tube type Modifier Thermal modifier pretreatment F (GaF) solid mode F (GaF) liquid mode 209, Solid PIN 10 µl 0.1%/0.05%/20 mg/l Pd/Mg/Zr 10 µl 10 g/l Ga(NO 3 ) 3 5 µl 10 g/l NaAc yes yes no no 5 µl 10 g/l Ga(NO 3 ) 3 Evaluation parameters Eval.- pixel Read time solid / liquid Spectral observation width Background correction [s] [nm] [pixel] F (GaF) solid mode F (GaF) liquid mode , IBC Temperature-time program:

4 Standard calibration solid AA : Liquid calibration standards Automatic preparation of the standards by the SSA 600L with liquid dosing unit Calibration standards 50/ 100/ 150/ 200/ 250 ng in graphite tube (stock solution 10 mg/l F in H 2 O) 3 measurements per calibration statistics, 6 measurements per solid sample Time peak area integration over 5 spectral pixels Linear calibration curve: R² = Standard 4: 200 ng F Sample 0.75mg Signal plot blue: Analyte signal

5 Standard 4: 200 ng F Sample 0.75mg Spectral environment 3D spectrum

6 Standard calibration liquid mode: Liquid calibration standards Automatic preparation of the standards by the liquid sampler MPE 60 Calibration standards 2/ 4/ 6/ 8/ 10 mg/l in the graphite tube (from stock solution 10 mg/l F in H 2 O) 3 measurements per calibration and sample statistics Time peak area integration over 5 spectral pixels Linear calibration curve: R² = Standard 4: 8 mg/l F Sample 0.75mg DF1 Signal plot blue: Analyte signal

7 Standard 4: 200 ng F Dentan 0.75mg VF1 Spectral environment 3D spectrum Results fluorine Sample Mode Weight in mg F concentration in mg/kg RSD in % Recovery rate (RR) in % solid 0,06 0, ± g/ 50ml 1260 ± 34 1,4 Sample 0.75mg liquid DF 1 Spiking 0, mg/l F g/ 50ml 1460 ± 210 1,8 DF 5 Spiking mg/l F 1,4 103 QC standard 4 solid Target: 200 ng F 183 ng F 2,3 91,6 iquid Target: 7.5 mg/l 8,2 ± 0,15 1,0 103

8 Summary With the use of a Xe short arc lamp as a lamp continuum source in the HR-CS AAS all absorption lines in the spectral range of nm are available for analytical evaluation. This is the prerequisite for the analytical use of molecule absorptions with a random wavelength. This makes it possible for the first time to use fine-structured molecule absorption spectra as gallium mono fluoride for the analytical determination of non-metals as in this case for fluorine. A CCD array is used as a detector, which guarantees a simultaneous and powerful background correction and offers additional spectral information for the analysis line to be examined by the simultaneous readout of 200 detector pixels. Thanks to this innovative simultaneous background correction, spectral interferences can be corrected on the analyte line regardless of the wavelength. Additional information about the sample is automatically available by the visualization of the simultaneously recorded spectral environment around the analyte wavelength. Method development and method optimization thus becomes much easier compared to classical AAS. The determination of fluorine in the organic matrix of the pharmaceutical tablet is unproblematic with the direct determination of solids and possible without further sample preparation. Calibration was performed with an aqueous fluoride standard as no fixed certified reference standard was available in the corresponding matrix. For the QC determination with the solid sampling technique, the same sample platforms were used which were also used for the determination of fluorine in the organic sample. The concentration result of the direct solid analysis is approx % below that of liquid analysis. A higher dilution of the sample for liquid analysis, thus of the organic matrix, also results in a higher analyte content of fluorine with an improved recovery rate. These results suggest that the organic matrix has an effect on the fluorine concentration. The measurement of an aqueous quality control standard after the organic sample also confirms the same recovery rate trend depending on the dilution of the matrix. For an accurate determination of the fluorine concentration with the solid technique, calibration with a certified reference material for fluorine in a similar matrix or with an internal reference sample with a known content is recommended. The determination of the total fluorine content with the liquid technique, on the other hand, can be performed easily and correctly after dissolving the tablet and subsequent analysis of the suspension after appropriate dilution. The very good recovery rates with the spiking of the suspension and also with the aqueous quality control standard of 103 % confirm this statement. Chemicals provided by Sigma Aldrich were used. The generated data may be re-used by Analytik Jena. Printout and further use permitted with reference to the source Analytik Jena AG Publisher: Analytik Jena AG Konrad-Zuse-Straße Jena Tel Fax info@analytik-jena.com