Le analisi dei metalli in traccia sono state condotte utilizzando sia l’assorbimento atomico a fornetto di grafite prodotto dalla GBC, e nel caso specifico il mod. GF3000, sia quello utilizzante la fiamma come mezzo di atomizzazione ,GBC mod. SB900. Inoltre anche lo spettrometro M SERIES AA, l’ autocampionatore FS95 Furnace, ed il blocco GF95Z con correzione Zeeman, sono risultati efficaci strumenti di lavoro.
Per l’analisi volta alla ricerca di taluni metalli, come ad esempio il rame, lo stronzio ed il piombo si è optato per condurre entrambe le tipologie di atomizzazione, scegliendo di volta in volta quella più idonea.
Qui di seguito saranno indicati i parametri operativi dello strumento, opportunamente divisi in due sezioni, in conseguenza della tipologia di atomizzazione utilizzata.
Nella prima esporremo i parametri impiegati per l’ utilizzo del fornetto di grafite, nella successiva invece quelli per l’ assorbimento a fiamma.
II.4.1.4.4: Parametri operativi AAS
Parametri operativi per elementi a fornetto:
1.
Element: Sr Measurement Mode: AbsorbanceWavelength: 460,7
Background Correction: Zeeman Number Of Resamples: 3
FURNACE PARAMETERS Cuvette Type: Coated
Injection Temperature: °C 0
Furnace Programme (secs) 72,0
Phase Temp Time Ramp Gas Gas Commands (°C) (sec) (°C/sec) Type Flow 1 100 30,0 10 2 0,2L/min 2 1000 20,0 150 2 0,2L/min 3 2800 3,0 0 2 Off RD TC 4 2850 3,0 0 2 0,2L/min TC
SAMPLING PARAMETERS Sampling: FS95/97
Working Volume: µL 20,0 Sample Volume: µL 20,0
Sample Preparation: Int. Dilution Intelligent Dilution Standard Preparation: Fixed Std Additions: None Slow Solution Uptake: Yes Slow Injection: Yes
CALIBRATION PARAMETERS Calibration Mode: Normal Line Fit: Quadratic Use Stored Calibration: No
Concentration Units: µg/L Scaled Units: µg/L Scaling Factor: 1,0000 Acceptable Fit: 0,995
Standard 1 5,0000 Standard 2 10,0000 Standard 3 20,0000
2.
Element: Ba Measurement Mode: Absorbance Wavelength: 553,6Background Correction: Zeeman Number Of Resamples: 3 • FURNACE PARAMETERS Cuvette Type: Coated
Injection Temperature: °C 0
Furnace Programme (secs) 67,0
Phase Temp Time Ramp Gas Gas Commands (°C) (sec) (°C/sec) Type Flow 1 90 10,0 10 2 0,2L/min 2 100 10,0 10 2 0,2L/min 3 1600 20,0 150 2 0,2L/min 4 1600 1,0 1 2 Off 5 2750 3,0 0 2 Off RD TC 6 2850 3,0 0 2 0,2L/min TC
• SAMPLING PARAMETERS Sampling: FS95/97 Automatic Spike Prep: No Working Volume: µL 20,0 Sample Volume: µL 20,0
Sample Preparation: Int. Dilution Intelligent Dilution Threshold: 100% Standard Preparation: Fixed Std Additions: None
Slow Solution Uptake: Yes Slow Injection: Yes Sampling Delay: No
• CALIBRATION PARAMETERS Calibration Mode: Normal Line Fit: Quadratic Use Stored Calibration: No
Concentration Units: µg/L Scaled Units: µg/L Scaling Factor: 1,0000 Acceptable Fit: 0,990
Standard 1 10,0000 Standard 2 25,0000 Standard 3 50,0000
3.
Element: Sb Measurement Mode: Absorbance Wavelength: 217,6Background Correction: Zeeman Number Of Resamples: 3
• FURNACE PARAMETERS Cuvette Type: Normal
Injection Temperature: °C 0 Furnace Programme (secs) 73,3
Phase Temp Time Ramp Gas Gas Commands (°C) (sec) (°C/sec) Type Flow 1 100 30,0 10 2 0,2L/min 2 1200 20,0 150 2 0,2L/min 3 2200 3,0 0 2 Off RD TC 4 2500 3,0 0 2 0,2L/min TC
• SAMPLING PARAMETERS Sampling: FS95/97 Working Volume: µL 20,0 Sample Volume: µL 20,0
Sample Preparation: Int. Dilution Intelligent Dilution Threshold: 100% Standard Preparation: Fixed Std Additions: None
Slow Solution Uptake: Yes Slow Injection: Yes Sampling Delay: No
• CALIBRATION PARAMETERS Calibration Mode: Normal Line Fit: Quadratic Use Stored Calibration: No
Concentration Units: µg/L Scaled Units: µg/L Scaling Factor: 1,0000
Acceptable Fit: 0,995 Rescale Limit: % 10,0 Failure Action: Flag and Continue
Standard 1 5,0000 Standard 2 25,0000 Standard 3 50,0000
4.
Element: Pb Measurement Mode: Absorbance Wavelength: 217,0Background Correction: Zeeman Number Of Resamples: 3
• FURNACE PARAMETERS Cuvette Type: Coated
Injection Temperature: °C 0 Furnace Programme (secs) 73,5
Phase Temp Time Ramp Gas Gas Commands (°C) (sec) (°C/sec) Type Flow 1 90 10,0 10 2 0,2L/min 2 120 20,0 10 2 0,2L/min 3 800 20,0 150 2 0,2L/min 4 800 1,0 1 2 Off 5 1200 3,0 0 2 Off RD TC 6 2500 3,0 0 2 0,2L/min TC
• SAMPLING PARAMETERS Sampling: FS95/97 Automatic Spike Prep: No Working Volume: µL 20,0 Sample Volume: µL 20,0
Sample Preparation: Int. Dilution Intelligent Dilution Threshold: 100% Standard Preparation: Fixed Std Additions: None
Slow Solution Uptake: Yes Slow Injection: Yes Sampling Delay: No
• CALIBRATION PARAMETERS Calibration Mode: Normal Line Fit: Quadratic Use Stored Calibration: No
Concentration Units: µg/L Scaled Units: µg/L Scaling Factor: 1,0000
Acceptable Fit: 0,985 Rescale Limit: % 10,0 Failure Action: Flag and Continue
Standard 1 2,0000 Standard 2 10,0000 Standard 3 20,0000
5.
Element: Cr Measurement Mode: Absorbance Wavelength: 357,9Background Correction: Zeeman Number Of Resamples: 3
• FURNACE PARAMETERS Cuvette Type: Coated Injection Temperature: °C 0 Furnace Programme (secs) 96,2
Phase Temp Time Ramp Gas Gas Commands (°C) (sec) (°C/sec) Type Flow 1 90 20,0 10 2 0,2L/min 2 120 30,0 10 2 0,2L/min 3 1200 20,0 150 2 0,2L/min 4 1200 1,0 0 2 Off 5 2500 3,0 0 2 Off RD TC 6 2700 3,0 0 2 0,2L/min TC
• SAMPLING PARAMETERS Sampling: FS95/97 Automatic Spike Prep: No Working Volume: µL 20,0 Sample Volume: µL 20,0
Sample Preparation: Int. Dilution Intelligent Dilution Threshold: 100% Standard Preparation: Fixed Std Additions: None
Slow Solution Uptake: Yes Slow Injection: Yes Sampling Delay: No
• CALIBRATION PARAMETERS Calibration Mode: Normal Line Fit: Quadratic Use Stored Calibration: No
Concentration Units: µg/L Scaled Units: µg/L Scaling Factor: 1,0000
Acceptable Fit: 0,985 Rescale Limit: % 10,0 Failure Action: Flag and Continue
Standard 1 1,0000 Standard 2 5,0000 Standard 3 10,0000
6.
Element: Cd Measurement Mode: Absorbance Wavelength: 228,8Background Correction: Zeeman Number Of Resamples: 3
• FURNACE PARAMETERS Cuvette Type: Coated Injection Temperature: °C 0 Furnace Programme (secs) 73,5
Phase Temp Time Ramp Gas Gas Commands (°C) (sec) (°C/sec) Type Flow 1 90 10,0 10 2 0,2L/min 2 120 20,0 10 2 0,2L/min 3 800 20,0 150 2 0,2L/min 4 800 1,0 1 2 Off 5 1000 3,0 0 2 Off RD TC 6 2500 3,0 0 2 0,2L/min TC •
• SAMPLING PARAMETERS Sampling: FS95/97 Automatic Spike Prep: No Working Volume: µL 20,0 Sample Volume: µL 20,0
Sample Preparation: Int. Dilution Intelligent Dilution Threshold: 100% Standard Preparation: Fixed Std Additions: None
Slow Solution Uptake: Yes Slow Injection: Yes Sampling Delay: No Number Of Washes: 1
•
• CALIBRATION PARAMETERS Calibration Mode: Normal Line Fit: Quadratic Use Stored Calibration: No
Concentration Units: µg/L Scaled Units: µg/L Scaling Factor: 1,0000
Acceptable Fit: 0,985 Rescale Limit: % 10,0 Failure Action: Flag and Continue
Standard 1 1,0000 Standard 2 5,0000 Standard 3 10,0000
7.
Element: Cu Measurement Mode: Absorbance • Lamp current (mA) = 4.0• Wavelenght (nm) = 324.7 • Slidt width (nm) = 0.5 • Standard:
Label Concentration Value STD1 Standard1 5 0.044 STD2 Standard2 25 0.19 STD3 Standard3 50 0.375 • Gf program:
8.
Element: As Measurement Mode: AbsorbanceWavelength: 193,7
Background Correction: Zeeman Height Number Of Resamples: 3
• FURNACE PARAMETERS Cuvette Type: Normal Injection Temperature: °C 0 Furnace Programme (secs) 98,2
Phase Temp Time Ramp Gas Gas Commands (°C) (sec) (°C/sec) Type Flow 1 90 30,0 10 2 0,2L/min 2 120 20,0 10 2 0,2L/min 3 1200 20,0 150 2 0,2L/min 4 1200 1,0 0 2 Off 5 2600 3,0 0 2 Off RD TC 6 2750 5,0 0 2 0,3L/min TC
• SAMPLING PARAMETERS Sampling: FS95/97 Automatic Spike Prep: No Working Volume: µL 10,0 Sample Volume: µL 10,0
Sample Preparation: None
Standard Preparation: Fixed Std Additions: Wet-mixed
Slow Solution Uptake: Yes Slow Injection: Yes Sampling Delay: Yes
• CALIBRATION PARAMETERS Calibration Mode: Std Additions Line Fit: Linear Use Stored Calibration: No
Concentration Units: µg/L Scaled Units: µg/L Scaling Factor: 1,0000
Acceptable Fit: 0,985 Rescale Limit: % 10,0 Failure Action: Flag and Continue Standard 1 2,0000 Standard 2 10,0000 Standard 3 20,0000 Final Temp.
Ramp time Hold time Gas type 1 2 90 10 20 Inert 3 120 10 20 Inert 4 500 5 15 Inert 5 500 1 1 None 6 2300 0.9 3 None 7 2400 0.5 0.5 Inert
Parametri operativi per elementi a fiamma: Rame: Cu mg/l 0.1 19 0.5 90 1 163 2 290 5 504 C =11 mA Λ = 325.8 EHT = -396 R² = 0.9972 Ferro: Fe mg/l 1 20 2 39 4 70 8 120 10 140 20 190 C =11 mA Λ = 249.8 EHT = -569 R² = 0.9998
Piombo: Pb mg/l 1 9 204 24 5 50 10 100 C = 6 mA Λ = 423.6 EHT = -412 R² = 0.9998 Stronzio: Sr mg/l 0.5 9 1 19 5 106 10 220 C =15 mA Λ = 461.6 EHT = -340 R² = 0.9996 Zinco: Zn mg/l 0.1 19 0.5 90 1 163 2 290 5 504 C = 6 mA Λ = 423.6 EHT = -412 R² = 0.9998