horiba FluoroMax-3, Operation Manual

Page: 68 / 220

FluoroMax-3 v. 3.1 (3 Mar 2006) Optimizing Data
5-2
Note:
Avoid thick cover-
slips, because the excita-
tion beam may not hit the
sample directly with a thick
coverslip.
Microscope coverslips are
useful, except that they are
not quartz, and do not
transmit UV light.
Warning:
Always read the Materials Safety Data Sheet
before using a sample or reagent.
Sample preparation
The typical
fluorescence or phosphorescence sample is a solution analyzed in a standard cuvette.
The cuvette itself may contain materials that fluoresce. To prevent interference, HO-
RIBA Jobin Yvon Inc. recommends using non-fluorescing fused-silica cuvettes that
have been cleaned as described above.
Small-volume samples
If only a small sample-volume is available, and the intensity of the fluorescence signal
is sufficient, dilute the sample and analyze it in a 4-mL cuvette. If fluorescence is weak
or if trace elements are to be determined, HORIBA Jobin Yvon recommends a capillary
cell such as our 50-
μ L or 250- μ L optional micro-sample capillary cells, which are spe-
cifically designed for a small volume. A 1-mL cell (5 mm × 5 mm cross-section) is also
available.
Solid samples
Solid samples usually are mounted in the Model 1933 Solid Sample Holder, with the
fluorescence collected from the front surface of the sample. The mounting method de-
pends on the form of the sample. See the section on “Highly opaque samples” for more
information on sample arrangement in the sample compartment.
•
Thin films and cell monolayers on
coverslips can be placed in the holder
directly.
•
Minerals, crystals, vitamins, paint chips,
phosphors, and similar samples usually
are ground into a homogeneous powder.
The powder is packed into the
depression of the Solid Sample Holder
(see next page for diagram). For very
fine powder, or powder that resists
packing (and therefore falls out when
the holder is put into its vertical
position), the powder can be held in place with a thin quartz coverslip, or blended
with potassium bromide for better cohesion.
•
A single small crystal or odd-shaped solid sample (e.g., contact lens, paper) can be
mounted with tape along its edges to the Solid Sample Holder. Be sure that the
excitation beam directly hits the sample. To keep the excitation beam focused on
the sample, it may be necessary to remove or change the thickness of the metal
spacers separating the clip from the block.