FluoroMax-3, The Worlds Most Sensitive Analytical Spectrofluorometer - Horiba Scientific

Topics Covered

Background
System Components
Features
      The Source
     The Slits
     The Excitation Monochromator
     The Reference Detector
     The Sample Chamber
     The Emission Monochromator
     The Emission Detector
     Computer Control
Accessories for the FluoroMax

Background

The FluoroMax-3 from Horiba Scientific is the worlds most sensitive analytical spectrofluorometer.

Figure 1. The FluoroMax-3 from Horiba Scientific.

System Components

Components of the FluoroMax-3 spectrofluorometer include:

• Xenon Arc Lamp and Housing Slits
• Excitation Monochromator
• Sample Compartment
• Emission Monochromator
• Emission Detector
• Reference Detector
• Electronics

Features

The FluoroMax-3 spectrofluorometer features:

• Water Raman signal to noise ratio: 2500:1
• Photon Counting for Ultimate Sensitivity
• Fast Scanning capability - up to 200nm/second
• Powerful Windows Software
• Method Files to recall complete experiment parameters
• Front Surface Detection Accessory
• Fluorescence Microscope Accessory
• Polarisation and Anisotropy Accessory
• Remote Measurement Capability using optical fibres

The Source

Starting with a xenon source that supplies prime UV performance, we mount the bulb vertically, since horizontal mounting leads to sagging of the arc that increases instability and decreases the useful life.

The xenon source is focused onto the entrance slit of the excitation monochromator with an elliptical mirror. Besides ensuring efficient collection, the reflective surface keeps all wavelengths focused on the slit, unlike lenses which have chromatic aberrations that make them totally efficient only at one wavelength.

As an option an additional, software selectable, xenon flash lamp can be fitted to enable phosphorescence studies.

The Slits

The slits themselves are bilaterally, continuously adjustable from the computer in units of bandpass or millimeters. This preserves maximum resolution and instant reproducibility.

The Excitation Monochromator

The excitation monochromator of the FluoroMax-3 spectrofluorometer is an aspheric design which ensures that the image of the light diffracted by the grating fits through the slit. The gratings themselves are plane, blazed gratings that avoid the two major disadvantages of the more common concave holographic gratings: poor polarisation performance and inadequate imaging during scans that throws away light. The unique wavelength drive scans the grating at speeds as high as 160 nm/s. The grating grooves are blazed to provide maximum light in the UV and visible region.

The Reference Detector

Before the excitation light reaches the sample in the FluoroMax-3 spectrofluorometer, a photodiode reference detector monitors the intensity as a function of time and wavelength. The photodiode detector has a wider wavelength response than the older, traditional rhodamine-B quantum counter, and requires no maintenance.

The Sample Chamber

A spacious sample chamber in the FluoroMax-3 spectrofluorometer is provided to allow the use of a long list of accessories for special samples, and encourages the user to utilise a variety of sample schemes.

The Emission Monochromator

All the outstanding features of the excitation monochromator are also incorporated into the emission monochromator. Gratings are blazed to provide maximum throughput in the visible region.

The Emission Detector

Emission detector electronics employ photon-counting for the ultimate in low-light-level detection. Photon counting concentrates on signals that originate from fluorescence emission, ignoring smaller signals originating in the detector tube (PMT). The more common method of analogue detection (used by lower performance fluorometers) simply adds noise and signal together, masking weak emissions.

The emission detector housing also contains an integral high voltage supply which is factory set to provide the signal to noise.

Computer Control

The entire control of the FluoroMax-3 originates in your PC and is transmitted through a serial link. On start-up, the system automatically calibrates and presents itself for new experiments, or stored routines instantly called from memory.

Accessories for the FluoroMax

A wide variety of accessories are applications orientated and most are interchangeable with the FluoroLog-3 system.

Source: Horiba Scientific

For more information on this source please visit Horiba Scientific