Purpose

This Reference Material can be used to calibrate the spectral response of a spectrofluorometer over the range 375 nm to 675 nm. It can also, over a limited concentration range, be used as a linearity check.

Description and Discussion

10mm far UV quartz fluorometer cuvettes with polished faces at 90° containing Quinine Sulfate solvated in perchloric acid, permanently sealed by heat fusion. The reference can be supplied with or without a perchloric acid blank. It is also available as sets of solutions with concentrations up to 1.0 mg/l for use as a linearity check. Quinine Sulfate Dihydrate in perchloric acid was one of the first reference materials developed for use in fluorescence spectroscopy, and is designated SRM 936a by NIST. The data supplied with the reference is based on its corrected fluorescence emission spectrum using an excitation wavelength of 347.5 nm:

Note: “Uncorrected” or raw spectra direct from the measurement system are rarely suitable for calibration purposes or inter-instrument comparisons, as they may be distorted by instrumental factors such as variations in source intensity, optical reflectivity and detector efficiency with changing wavelength. “Corrected” spectra are obtained by removing these effects instrumentally or by software techniques.

In the Calibration Certificate supplied, the relative emission intensity Eλ is tabulated at 5 nm intervals. For the instrument under test, the correction factor S at wavelength λ is then given by

S = Rλ/Eλ

Where Rλ is the instrument reading at wavelength λ and

Eλ is the certified relative intensity value at wavelength λ from the table. The corrected emission value at a given wavelength for other fluorescent materials, under the same measurement conditions and in the same spectral region, can then be determined by

E = R/S

Where R is the instrument reading and S is the correction factor at the measurement wavelength.

At low concentrations (up to 1 mg/l, this material can also be used to check the linearity of response of a spectrofluorometer, and a set of references with concentrations 0.25, 0.5, 0.75 and 1 mg/l is available for this purpose.

Typical spectra

 

 

Catalogue Number

  Catalogue  Number

Quinine Sulfate Spectral Response & Linearity Set (4 concentrations)
0.25, 0.5, 0.75 and 1 mg/l Quinine Sulfate in perchloric acid + perchloric acid blank cell

RM-4QS00

Quinine Sulfate Spectral Response & Linearity Set (3 concentrations)
0.25, 0.5 and 1mg/l Quinine Sulfate in perchloric acid + perchloric acid blank cell

RM-3QS00

Quinine Sulfate Spectral Response & Linearity Set (2 concentrations)
0.5 and 1 mg/l Quinine Sulfate in perchloric acid + perchloric acid blank cell

RM-2QS00

Quinine Sulfate Spectral Response Cell
1 mg/lQuinine Sulfate in perchloric acid

RM-1QS

Quinine Sulfate Spectral Response Cell + Blank
1 mg/l Quinine Sulfate in perchloric acid + perchloric acid blank cell

RM-1QS00