Temperature calibration graph

For fixed time assays this most frequently involves the use of standards and a calibration graph. Some methods, e.g. the use of the molar absorbance coefficient in spectrophotometry, do not requite standards and giiNometric methods permit the calculation of molar concentration from the volume of gas (1 gram mole of gas occupies 22.4 litres at standard temperature and pressure, STP). 

Figure 11.34 Calibration graph of the fluorescence lifetime (solid line) and blackbody radiation (dashed line) versus temperature.

A calibration graph was prepared from known aliquots of pure gibberellic acid and a linear relationship established over a concentration range of 0 to 4 mg. per 100 ml. with a reaction time of 75 minutes and a temperature of 20° C. The... 

Nimodipine in plasma was determined by a GC method [17]. Plasma was treated with 2 M NaOH after addition of the internal standard, and then extracted with toluene. The column (10 m x 0.31 mm) consisted of cross-linked 5% phenylmethyl silicone, and the method used temperature programming from 90°C (held for 1 min) to 255°C at a heating rate of 25°C/min. Helium was used as a carrier gas, and the N-P detection mode was employed. The calibration graph was linear from 2 to 50 ng/mL, and the detection limit was 0.5 ng/mL. 

Although it is possible to measure directly Mn in body fluids at normal concentrations of 18—180 nmol 1 I (1—lOpgl-1) it is difficult to achieve a precision of better than 0.10 RSD. The elimination of the considerable molecular absorption interferences requires strict control of ETA ashing temperatures and a good background correction system, and the variable condensed phase matrix interferences from the inorganic constituents necessitates the use of standard additions for calibration [64], Even this approach may not yield a viable method due to curvature of the calibration graph at very low absorbances, particularly with a diluted blood matrix [65],... 

To calibrate at 0°C/min, construct a graph of the onset of melting temperature against heating rate and extrapolate back to the onset temperature for 0°C/min. This value is then entered into the temperature calibration software of the DSC. 

Second method about 400-500 mg of sample were treated with HCl and extracted into toluene and cysteine, and back-extracted into toluene. The extract was dried with anhydrous Na2S04. The separation was by capillary gas chromatography (column of 30 m length, internal diameter of 0.53 mm stationary phase S.P.B. 608 Supelchem, 0.50 pm film thickness injection of 1 pL temperature of the injector of 250 °C, temperature of the ECD detector of 350°C, column temperature of 90°C N2 as carrier gas at 10 mLmin Ar/ CH4 as make up gas type at 60 mLmin ). Calibration was by calibration graph with CH3HgCl in toluene C2H5HgCl was used as internal standard. 

Distillation was performed on a sample of 300 mg by addition of 0.5 mL H2SO4 (9 mol L ) in 20% KCl in H2O at a temperature of 145 °C distillation recovery was ca. 90%. Derivatization was by addition of 1% NaBEt4 in acetic acid. Separation was by gas liquid chromatography (column of 0.5 m length, internal diameter of 4 mm Chromosorb W AW-DMSC 60-80 mesh, loaded with 15% OV-3 stationary phase temperature of the injector of 500 °C, detector temperature at 20 °C column temperature of 100 °C He as carrier gas at 40 mL min ). Detection was by cold vapour atomic fluorescence spectrometry. Calibration was by calibration graph and standard additions using MeHgCl calibrant in Milli-Q water. 

Ca. 3.5 g sediment were extracted by supercritical fluid extraction (CO2 and 20% methanol) after HCl addition. The extraction recovery for TBT (verified with a TBT-spiked sediment) was (82 + 6)%. Grignard derivatization was performed, using 2 mol L EtMgCl in tetrahydrofuran. Separation was by CGC (column of 30 m length, internal diameter of 0.25 mm, DB-5 as stationary phase, 0.1 pm film thickness He as carrier gas at 2 mL min injector temperature at 40 °C column temperature ranged from 40 to 290 °C). Detection was FPD (temperature of 225 °C). Calibration was carried out with butyltin chloride calibrants calibration graph and standard additions of tripropyltin as internal standard. 

Second method ca. 0.5 g sediment was extracted with methanol/tropolone after addition of HCI. Tripropyltin was added as internal standard. Derivatiza-tion was performed by addition of pentylmagnesium bromide (2 mol L ) followed by clean-up with silica gel. Separation was by CGC (column of 25 m length, 0.2 mm internal diameter, methylphenyl silicon as stationary phase, 0.11 pm film thickness He as carrier gas at 130 mL min injector temperature at 260 °C column temperature ranging from 80 to 280 °C detector (transfer line) temperature at 280 °C). Detection was by mass spectrometry. Calibration was by calibration graph, using butyltin chloride compounds as calibrants. 

Ca. 1 g sample was extracted by supercritical fluid extraction with CO2 and a mixture of acetic acid and 0.2% tropolone with hexane as solvent (pressure of 50 atm, temperature of 50 Q. Ethylation was carried out with 2 mol L ethylmagnesium chloride. TPeT was added as internal standard. Separation was by capillary GC (column of 30 m length, 0.25 mm internal diameter, DB-17 as stationary phase, 0.25 pm film thickness H2 as carrier gas at 5 mLmin N2 as make-up gas at 30 mLmin injector temperature of 250 °C column temperature ranging from 60 to 280 °C). Detection was by FPD (detector temperature of 300 °C). Recoveries were assessed by standard additions results were (82 4)% for DBT, (75 + 2)% for TBT and (65 + 3)% for TPhT. Calibration was by calibration graph and standard additions, using the calibrants provided by SM T. 

---