Determination of Toxic Elements in Durian and Jackfruit Using an Agilent Automated ICP-MS System According to China GB 5009.268

Significance of the topic

Trace toxic elements (As, Cd, Hg, Pb) in fruit are tightly regulated because even low-level contamination can affect food safety and trade. For exporters to large markets such as China, routine, fast, and reliable testing is essential to comply with stringent maximum limits and to avoid shipment delays or rejections. Automated, high-throughput analytical workflows reduce manual handling errors, improve laboratory productivity, and support consistent compliance with national standards.

Objectives and study overview

This application note describes development and validation of a method to determine arsenic, cadmium, mercury, and lead in durian and jackfruit following the China GB 5009.268 standard. The work aims to demonstrate that an automated Agilent ICP-MS workflow (7900 ICP-MS combined with ADS2, AVS and SPS 4 autosampler) meets regulatory requirements for sensitivity, accuracy, precision and robustness while increasing throughput for routine export testing.

Methodology

• Sample collection and preparation: Representative samples of edible pulp were taken from export containers, homogenized and aliquots (~0.5 g) were subjected to closed-vessel microwave digestion (Multiwave 500) with HNO3 and a small volume of HCl. A gold solution was added prior to digestion to stabilize mercury and reduce memory effects.
• Calibration and standards: A multi-element stock was diluted to prepare a 7-point calibration (0.05–10 µg/L) automatically using ADS2. Internal standards (6Li, Sc, Ge, Rh, In, Tb, Lu, Bi) were mixed online via the AVS.
• ICP-MS measurement: Elements were measured on an Agilent 7900 ICP-MS. Arsenic was measured in He KED mode to minimize 40Ar35Cl+ interferences; other analytes were measured in no-gas and He modes as appropriate. Instrument autotuning and method parameters were optimized for food matrices.
• Quality control: Method performance was tested with matrix spikes at 5, 10 and 25 µg/kg (where a unified LOQ of 5 µg/kg was applied), blanks between runs, and monitoring of internal standard recoveries across >70 consecutive samples.

Used instrumentation

• Agilent 7900 ICP-MS with ORS4 and He collision capability
• Agilent ADS2 Advanced Dilution System for automated calibration and reactive dilutions
• Agilent AVS (Advanced Valve System) for automated probe rinsing and online mixing
• Agilent SPS 4 autosampler
• MicroMist nebulizer, temperature-controlled quartz spray chamber, one-piece quartz torch (2.5 mm injector)
• Multiwave 500 microwave digestion system (Anton Paar)

Main results and discussion

Linearity, sensitivity and stability:

• Automated 7-point calibrations (0.05–10 µg/L) showed excellent linearity (R² ≥ 0.995) using 1/x weighting and back-calculated concentrations within 90–110%.
• Internal standard recoveries remained within ±20% over sequences of more than 70 samples, indicating long-term stability and minimal carryover due to the AVS rinsing strategy.

Accuracy, precision and LOQ:

• A unified LOQ of 5 µg/kg was applied for all four target elements. Matrix spike recoveries at 5 µg/kg ranged approximately from 71% to 115% depending on element and matrix, meeting AOAC Appendix F and GB/T 27417-2017 acceptance criteria.
• Average recoveries (examples): in durian—As ~85%, Cd ~84%, Hg ~76%, Pb ~103%; in jackfruit—As ~93%, Cd ~107%, Hg ~94%, Pb ~95%.
• Repeatability (RSDr) and reproducibility (RSDR) were consistently low: RSDr ~3–8% (average ~5.5%), RSDR ~5–9% (average ~7.5%) across spike levels, demonstrating robust precision across analysts and days.

Throughput and operational benefits:

• Automation reduced hands-on time and produced a sample throughput of approximately 1.5 minutes per sample for calibration preparation and analysis steps, improving efficiency for high-volume food testing.
• ADS2 enabled automated multi-point calibration preparation and result-based reactive dilutions, eliminating time-consuming manual dilution steps and minimizing contamination risk.

Practical benefits and applicability

• The validated automated ICP-MS workflow meets Chinese regulatory performance requirements for LOQ, accuracy and precision for As, Cd, Hg and Pb in tropical fruit matrices.
• Automation reduces labor, decreases potential for human error, and increases sample throughput—advantages that are critical for export testing laboratories handling large volumes.
• The use of gold to stabilise mercury, AVS probe rinsing, and ORS/He collision mode for As are practical measures that improve data quality for problematic analytes and high-salt matrices.

Future trends and potential uses

• Greater integration of automated sample handling, dilution and instrument control will continue to streamline routine food safety testing and reduce per-sample cost.
• Advances in interference-management technologies and collision/reaction cell chemistries will further expand reliable quantification of challenging elements in complex matrices without extensive sample preparation.
• Coupling automated ICP-MS workflows with laboratory information management systems (LIMS) and remote monitoring will improve traceability, QA/QC and turnaround time for high-throughput testing required by global trade.

Conclusion

The Agilent 7900 ICP-MS combined with ADS2, AVS and SPS 4 autosampler provides a validated, automated analytical workflow capable of reliably quantifying As, Cd, Hg and Pb in durian and jackfruit at a unified LOQ of 5 µg/kg. The method demonstrated excellent linearity, acceptable recoveries, and strong repeatability and reproducibility while increasing throughput and reducing manual workload—attributes suited to export-focused food testing laboratories needing compliance with stringent regulatory limits.

References

1. National Health Commission of the People's Republic of China; State Administration for Market Regulation. GB 5009.268-2025: National Food Safety Standard—Determination of Multi-elements in Foods. Beijing, China, 2025.
2. Standardization Administration of the People's Republic of China. GB/T 27417-2017: Conformity assessment—Guidance on validation and verification of chemical analytical methods. Standards Press of China, 2017.
3. Kumaraswamy S., Selvi S. V. Assessment of Nutritional Value and Potential Metal Toxicity in Fruit of Artocarpus Altilis (Parkinson) Fosberg (Seedless) in India. International Research Journal of Plant Science 2020, 11(1), 1–8.
4. Chinese Agricultural Information Institute. China Agricultural Outlook on Dairy, Meat and Fruit, 2020–2029. 2020.
5. National Health Commission of the People's Republic of China; State Administration for Market Regulation. GB 2762-2025: National Food Safety Standard—Maximum Levels of Contaminants in Foods. Beijing, China, 2025.
6. Agilent Technologies. Agilent 7900 ICP-MS: Powerful, Flexible, Single-Quadrupole ICP-MS. Brochure 5991-3719EN.
7. Nelson J., O'Neill E., Block D., Heckle S. Determination of Heavy Metals and Trace Elements in Alternative Meats Per EAM 4.7 Method for ICP-MS. Agilent Technologies application note 5994-5181EN.
8. Agilent Technologies. Capabilities and Operation of the Advanced Dilution System 2. Technical overview 5994-7211EN.
9. AOAC INTERNATIONAL. Appendix F: Guidelines for Standard Method Performance Requirements. In Official Methods of Analysis of AOAC INTERNATIONAL, 22nd ed., 2023.