Plant growth regulators (PGRs), as important compounds that can influence plant hormone signaling, cell division, organ differentiation, and reproductive development, have extremely high application value in modern agricultural systems. Because their functions are similar to natural plant hormones and they are commonly used as agrochemicals, they are considered mandatory chemical substances in pesticide residue monitoring systems. To ensure detection accuracy, the purity, source, and stability of standards are core to the analytical quality control system.
What Are Plant Growth Regulators?
Plant growth regulators refer to a class of chemical substances that can affect plant physiological activities at extremely low concentrations, including natural hormones and their synthetic structural analogues. These regulators can control cell proliferation, cell elongation, organ formation, fruit ripening, and stress response.
Typical mechanisms of action of regulators are as follows:
- Cell division promoters (e.g., 6-benzylaminopurine): promote bud growth, increase tillering rate, and regulate organ differentiation;
- Growth inhibitors (e.g., maleic hydrazide): inhibit excessive growth, limit internode elongation, and enhance plant shape stability;
- Growth promoters (e.g., gibberellic acid GA3): promote stem elongation, break seed dormancy, and induce flowering.
These regulators are widely used in crop yield increase, flower cultivation, fruit tree cultivation, and spray growth regulation, thus becoming important monitoring targets in pesticide residue detection systems.
Why Are High-Purity Plant Growth Regulator Standards Essential?
The accuracy of pesticide residue analysis is highly dependent on the purity, reliability, and stability of the quantitative reference. PGRs typically possess complex structures, are easily degraded, and readily interact with matrix components. Therefore, high-purity standards are crucial to ensure:
- Accuracy of quantitative results: The establishment of standard curves relies on traceable purity standards;
- Consistency of results across laboratories: Ensuring consistent response factors across different times and batches;
- Meeting regulatory compliance requirements: PGRs are incorporated into numerous national and international testing standards, such as food pesticide residue testing and export product quality certification;
- Avoiding interference from impurities: Controlling peak overlap and mass spectrometry response distortion caused by matrix effects.
Alfa Chemistry's plant growth regulator standards undergo rigorous purity certification, ensuring analytical laboratories have a stable and reproducible measurement foundation for method development and quality control.
What Are Some Common Plant Growth Regulators?
The table below summarizes the most common PGRs used in pesticide testing, for which Alfa Chemistry provides standards, and their analytical significance.
Table 1. Representative Plant Growth Regulators and Their Analytical Significance
| Plant Growth Regulator | Chemical Class | Primary Agronomic Function | Analytical Considerations | Common Analytical Techniques |
| 6-Benzylaminopurine (6-BAP) | Cytokinin | Promotes bud differentiation; enhances tissue culture proliferation | Strong matrix interference; requires high-sensitivity quantification | LC-MS/MS, HPLC |
| Maleic hydrazide (Daminozide) | Growth inhibitor | Suppresses excessive elongation; improves plant architecture | Listed as a key monitored compound; requires low detection limits | LC-MS/MS |
| Gibberellic Acid (GA3) | Gibberellin hormone | Breaks seed dormancy; promotes stem elongation | Easily degraded; demands highly stable reference standards | HPLC, LC-MS |
| Indole-3-acetic Acid (IAA) | Auxin | Regulates cell elongation | Highly photosensitive; requires protected handling | LC-MS |
| Methyl Jasmonate (MeJA) | Jasmonate hormone | Induces plant defense responses | High volatility; suitable for GC-based methods | GC-MS |
| Paclobutrazol | Growth inhibitor | Controls plant height; enhances stress tolerance | Routine target compound in residue monitoring | LC-MS/MS |
These regulators are frequently used in the precision cultivation of vegetables, fruits, grains, flowers, and greenhouse crops, thus requiring high-frequency detection in export inspection, food safety supervision, and agricultural environmental monitoring.
How to Establish a Reliable PGR Detection Method in A Pesticide Detection System?
Laboratory detection of plant growth regulators typically involves the following key steps:
A. How to optimize sample pretreatment?
- Solid-phase extraction (SPE) or QuEChERS are common methods for handling complex plant or soil matrices.
- Distant solid-phase purification (d-SPE) can effectively reduce co-extractants such as pigments and lipids.
- pH adjustment is crucial for weakly acidic/weakly basic regulators and can significantly improve recovery rates.
B. How to select chromatographic conditions?
- LC-MS/MS is the most mainstream method and is suitable for thermally unstable or highly polar regulators.
- HPLC-UV/FLD is suitable for molecules with good stability and high responsiveness, such as 6-benzylaminopurine;
- GC-MS is suitable for volatile regulators, such as jasmonic acid esters.
C. How to ensure accuracy in quantitative strategies?
- External standard quantification should be performed using high-purity, similar standards.
- Isotope internal standard correction is recommended for complex matrices.
- All methods must be validated for linearity, LOD/LOQ, recovery, and precision.
Alfa Chemistry's plant growth regulator standards offer batch-to-batch consistency and reliable stability, significantly improving the reproducibility of laboratory quantification.
What Is the Role of PGRs in Regulation and Agricultural Auality Control?
With increasingly stringent global requirements for food safety and agricultural input management, many national regulatory systems have included plant growth regulators in pesticide residue testing. For example:
- Exported agricultural products must meet international MRL standards (such as EU and Codex);
- Gibberellic acid and 6-BAP, widely used in the fruit and vegetable industry, must undergo residue risk assessment;
- The use of growth inhibitors in greenhouse agriculture can lead to cumulative risks, thus increasing the demand for testing.
High-quality standards are fundamental supporting materials for regulatory development, laboratory accreditation, method development, and industry self-inspection systems.
How to Select Plant Growth Regulator Standards for Pesticide Analysis?
The laboratory should be evaluated based on the following dimensions:
a. Does it possess purity certification (≥98% or higher)?
b. Does it provide a traceability certificate of account (CoA) and spectral data?
c. Is it compatible with multiple testing environments such as LC-MS and GC-MS?
d. Does it have small packaging formats suitable for method development?
e. Does it include commonly tested varieties?
Alfa Chemistry's plant growth regulator standards cover a wide range of commonly tested varieties, meeting the needs of the entire process from method development to quality control in pesticide analysis.
Conclusion
Plant growth regulators play a crucial role in modern agriculture by regulating growth, increasing yield, and improving quality. They are also essential chemical substances that must be detected in food safety and pesticide residue monitoring systems. High-purity standards have irreplaceable core value in analytical method establishment, quantitative reliability, and global regulatory compliance. With the standards and reagents provided by Alfa Chemistry, laboratories can build more stable, accurate, and efficient analytical systems to meet increasingly stringent agricultural and food regulatory requirements.