A Simple and Efficient Solution for HPLC Sensitivity: The WelView Photo Chemical Reactor
Introduction
In chromatographic analysis, achieving high sensitivity and selectivity for trace-level analytes within complex matrices is a foundational challenge towards accurate determination. For analytes with weak native fluorescence, poor UV response, or unstable signal behavior, direct HPLC-FLD analysis may not always deliver the reliability required for routine testing. In these cases, derivatization becomes an effective strategy to improve detection performance and expand the analytical scope of the method.
Photochemical post-column derivatization utilizes high-intensity UV light as a clean, reagent-free catalyst, addressing operational drawbacks from electrochemical post-column derivatization such as significant baseline noise, complex multi-pump instrumentation, corrosive reagents, and hazardous chemical waste. This significantly enhances the response of target analytes under fluorescence, UV, electrochemical, and chemiluminescence detection.
Product Overview
The WelView Photo Chemical Reactor developed by Welch Materials is designed for continuous post-column photochemical derivatization. It features a color display for instrument status monitoring, along with UV lamp fault detection and leak alarm functions, significantly improving derivatization performance and extending the service life of the UV lamps.
During use, the instrument is installed between the column and the detector. When aflatoxins are analyzed by HPLC-FLD under WelView, no chemical reagents are required and fluorescence intensity of aflatoxins B1 and G1 is effectively enhanced.
In addition to aflatoxin, the system can also be applied for numerous barbiturates, amino acids, peptides, vitamins, sulfonamide drugs, and traditional Chinese medicinal materials. It also significantly enhances the fluorescence intensity of sulfonamides, including sulfadiazine (SDZ), sulfapyridine (SPD), sulfamerazine (SMR), sulfadimidine (SM2), sulfamethoxydiazine (SMD), and sulfaquinoxaline (SQX), when analyzing sulfonamide drugs.
Key Advantages
| Advantage | Post-column derivatization | Pre-column derivatization | ||
| Photo chemical reactor | Electrochemical reactor | |||
| No chemical reagents required; safe to operate | √ | × | × | |
| Extends the service life of HPLC instruments (no corrosive liquids) | √ | × | × | |
| No flushing step required | √ | × | × | |
| No derivatization temperature control required | √ | × | × | |
| Effectively minimizes interference from compounds with similar retention times | √ | × | √ | |
| High sensitivity | √ | √ | √ | |
Note: Aflatoxins are derivatives of dihydrofuranocoumarin. Some components in traditional Chinese medicines belong to the same class of compounds and may cause interference. This interference can be eliminated by comparing the chromatograms with and without derivatization.
Parameters
| Maximum tubing pressure resistance | 3000 psi (207 bar) | Anti-interference | Equipped with anti-electromagnetic interference capability |
| Maximum flow rate | 3 mL/min | Temperature control | Air cooling |
| Derivatization tubing I.D. | 0.25 mm | Fittings | PEEK |
| Derivatization tubing length | 24 m | Lamp holder | With power switch |
| Tubing material | High-purity FEP, with excellent solvent resistance and virtually no cross-contamination (currently one of the polymers with the lowest contamination level) | Power supply | 220 V / 50 Hz |
| Power consumption | 30 W | ||
| UV lamp | Dual-lamp design for improved derivatization performance | Dimensions | 88 × 404 × 80 mm (W × D × H) |
| UV lamp lifetime | Approximately 7,000 hours; a prompt will appear when the lamp is nearing the end of its service life | Weight | Approx. 3.0 kg |
| Leak alarm | Screen display, audible alarm, and warning light | Operating temperature | 0-45 °C |
| Display language | Chinese or English | Relative humidity | ≤85% |
This product complies with AOAC 2005.08, AOAC 2008.02, AOCS Aa 11-05, Food Regulation Notice No. 0981800370 (Taiwan, China), the European Pharmacopoeia 2.8.18 standard analytical method, and the Chinese Pharmacopoeia 2020 Edition, Vol. IV Methods for Determination of Mycotoxins.
Applications
1. Determination of Aflatoxins
Aflatoxins B1 and G1 are inherently highly fluorescent, but when they come into contact with water, fluorescence quenching occurs and their fluorescence is essentially lost, making them difficult to detect by HPLC. Photochemical derivatization can be used to enhance the fluorescence of aflatoxins B1 and G1.
- Column: Ultisil XB-C18, 5 µm, 4.6×150 mm
- Mobile Phase: Methanol : water = 45:55
- Flow Rate: 0.8 mL/min
- Detector: FLD, excitation: 360 nm, emission: 440 nm
- Injection Volume: 20-100 µL
- Derivatization: Photo chemical reactor connected after the column and before the FLD
2. Determination of Sulfonamide Drugs
Sulfadiazine (SDZ), sulfapyridine (SPD), sulfamerazine (SMR), sulfadimidine (SM2), sulfamethoxydiazine (SMD), and sulfaquinoxaline (SQX) are not inherently fluorescent, but after derivatization by the photo chemical reactor, these six sulfonamides become fluorescent.
- Column: Ultisil XB-C18, 5 µm, 4.6×250 mm
- Flow Rate: 1.0 mL/min
- Detector: FLD, excitation: 232 nm, emission: 400 nm
- Injection Volume: 20-100 µL
- Gradient program:
Time (min) Acetonitrile (%) Water (%) 0~15 18 82 15~25 40 60 25~30 18 82
Installation and Maintenance
- Remove all components from the package and connect the power cord to the instrument.
- Unscrew the two PEEK fittings from the stainless-steel union.
- The tubing has no directional restriction. Connect one end of the tubing to the chromatographic column and leave the other end disconnected from the detector for the time being. Flush the system with mobile phase for 5 minutes, and then connect it to the fluorescence detector.
- Turn on the power switch and start the UV lamp. After the baseline becomes stable, begin sample injection and analysis.
- After the experiment, flush the system together with the column and store it with a high proportion of organic solvent (>70% methanol or acetonitrile).
- If the instrument will not be used for a long period, flush it once every 3 to 4 months and store it with a high proportion of organic solvent.
WelView Photo Chemical Reactor
$4,560.00 USD
