1X-ray fluorescence spectrometerEnvironmental preparation and safety protection

environmental conditions

The laboratory needs to have good ventilation conditions to avoid strong electromagnetic interference.

The temperature should be controlled at 20-25 ℃ and the relative humidity should be below 60% to prevent condensation inside the instrument or moisture from affecting the components.

The operating table should be stable and kept away from vibration sources to ensure the stability of the instrument.

safety protection

Radiation protection: X-rays are radioactive, and all personnel must receive safety training and wear personal protective equipment such as lead goggles and protective clothing before operation.

Warning signs: Clear radiation warning signs should be set up around the instrument, and control areas (radiation dose<2.5 μ Sv/h) and supervision areas (radiation dose<0.5 μ Sv/h) should be designated.

Personal dose monitoring: Operators need to be equipped with personal TLD dosimeters and establish annual cumulative dose records, following the ALARA principle (reasonable and feasible minimum radiation).

2、 Instrument inspection and startup preheating

Instrument inspection

Before starting up, check whether the appearance of the instrument is intact, whether the connections of each component are tight, and ensure that the power supply, cooling system, computer interface, etc. are firmly connected.

Check if the status indicator lights of key components such as the vacuum system, light tube, and detector are functioning properly.

Power-on and warm-up

Startup sequence:

Turn on the main power of the instrument and start the control software (such as SPECTRAPlus, M4 Tornado, etc.).

Wait for the instrument self-test to complete and confirm that the initial states of the light tube, detector, vacuum system, etc. are normal.

Preheating requirements:

The preheating time is generally 5-15 minutes, depending on the instrument model and ambient temperature. For example, the Bruker M4 Tornado needs to be preheated until all four indicator lights turn green.

During the preheating process, the instrument will perform filament current and voltage calibration and equipment tube centering calibration to ensure stable operation of the light tube.

3、 Sample preparation and loading

sample preparation

Solid sample:

The surface should be smooth and flat, avoiding dust, oil stains, or oxidation layers. If necessary, grind with tungsten carbide until the surface roughness Ra is less than 0.8 μ m.

Metal samples need to eliminate surface segregation effects to ensure compositional uniformity.

Powder sample:

Using boric acid edge compression method, pressure>20T, hold pressure for 120 seconds to ensure no pores in the compression.

The powder particle size should be less than 75 μ m to reduce the impact of particle effects on the detection results.

Liquid sample:

Seal with a specialized polyethylene cup and 6 μ m polyester film to prevent evaporation or leakage.

Ensure that the sample is free of bubbles and well sealed to avoid leakage in a vacuum environment.

Sample loading

Place the prepared sample into the sample tray or automatic sampler, and confirm that the sample size and type are consistent with the analytical parameters.

Adjust the sample position so that the test area is located at the center of the detection window, and close the sample chamber door.

For micro area analysis (such as μ - XRF), a high-precision stage should be used and the sample position should be adjusted to the focal point through software.

4、 Instrument setup and calibration

Parameter Settings

Set measurement mode (qualitative/quantitative analysis), tube voltage (usually 15-50kV), tube current (1-1000 μ A) and other parameters based on sample properties and analysis requirements.

Adjust the spot size, collimator angle, and measurement time (single point scanning time can be set to 7-10ms).

For liquid samples, helium mode should be selected to prevent volatilization; For solid samples, vacuum mode can be selected according to the requirements to improve detection sensitivity.

instrument calibration

Energy calibration: Perform daily calibration after power on, using standard samples (such as Cu-K α: 8.04keV, Ag-K α: 22.1keV) to calibrate the instrument's energy scale.

Quantitative calibration: Select a standard sample (such as NIST SRM 610 glass standard sample) that matches the sample matrix for calibration based on the type of analyzed element.

Calibration curve: Import or create calibration curves suitable for the sample to ensure the accuracy of quantitative analysis.

5、 Data collection and processing

data collection

Click the "Start Measurement" button, and the instrument will automatically scan the sample and record the fluorescence spectrum data.

During the measurement process, avoid moving the sample or instrument to prevent data distortion.

For surface scanning or panoramic analysis, it is necessary to set the scanning range, step size (such as 50 μ m), and acquisition parameters to ensure that the data covers the complete analysis area.

data processing

Qualitative analysis: Identify element peaks through spectral matching, and confirm the type of element by combining Moseley's law (√ (1/λ)=k (Z − σ)).

Quantitative analysis:

Use the FP method (basic parameter method) or empirical coefficient method to solve the spectrum and calculate the percentage of element content.

Correct abnormal data, eliminate background noise and interference peaks, and improve data reliability.

Data export: Export reports or save data to a database according to requirements, supporting formats such as Excel and CSV.

6、 Cleaning and Shutdown

Sample cleaning

After the measurement is completed, promptly clean the sample residue to avoid contaminating the interior of the instrument.

For liquid samples, it is necessary to thoroughly clean the sample cup and sealing film to prevent cross contamination.

Instrument shutdown

Turn off the instrument power in the correct order, first turn off the software, and then turn off the main power.

Regularly check the vacuum seal, light tube status, and dust collector to ensure long-term stable operation of the instrument.

Record instrument usage logs, including running time, maintenance status, and abnormal alarm information.

7X-ray fluorescence spectrometerQuality Control and Maintenance

quality control

Daily check: Perform energy calibration to verify instrument stability.

Weekly verification: Use standard samples to verify the detection limit and ensure instrument sensitivity.

Quarterly testing: Conduct repetitive testing (RSD<1.5%) to evaluate instrument precision.

routine maintenance

Regularly clean the surface and internal components of the instrument to maintain a pollution-free optical path.

Replace vulnerable parts such as batteries and filters to ensure the normal operation of the instrument.

Avoid frequent switching of the light tube, and switch it on and off at most once a day to extend its lifespan.