SDXNS200 Combustion Ion Chromatography Analyzer(CIC): A Comprehensive Solution Fully Aligned with ISO 20999:2026 and GB/T 31126.3-2026 for Dual-Standard Compliance Testing
PFAS (per- and polyfluoroalkyl substances) are widely used in textiles, footwear, outdoor products, and other consumer goods due to their excellent water‑, oil‑, and stain‑repellent properties. However, with thousands of PFAS congeners, targeted analytical methods such as LC‑MS/MS alone cannot cover all potential substances of concern. In recent years, regulators and international standards organizations in Europe and North America have increasingly emphasized total fluorine (TF) testing – determining the total amount of fluorine released from all fluorinated compounds in a sample – as a crucial screening tool for PFAS.
In April and June 2026, ISO/TC 38 (Textiles) and TC 209/SC 1 (National Technical Committee on Textiles of Standardization Administration of China) successively issued two key standards:
ISO 20999:2026 — Textiles — Determination of total halogens in textiles – Combustion and ion chromatography method
GB/T 31126.3-2026 — Textiles — Determination of perfluoro and polyfluoro compounds – Part 3: Combustion‑ion chromatography method
For the first time, these standards establish unified technical specifications for the determination of total halogens in textile products using combustion‑ion chromatography (C‑IC), marking a global shift in PFAS regulation from target‑substance control toward holistic fluorinated substance risk management.
This method can be used for the overall assessment of PFAS content in textiles to determine compliance with OEKO‑TEX® certification requirements. Notably, OEKO‑TEX® tightened the total fluorine limit from 100 ppm to 50 ppm in 2026, with the new regulation effective June 1, 2026. ISO 20999:2026 specifies a quantification limit of 10 mg/kg for fluorine, fully meeting the latest OEKO‑TEX® requirement of total fluorine content not exceeding 50 mg/kg.
SDXNS200 High-Temperature Combustion Ion Chromatography Analyzer: Full Alignment with Both Standards
Sundy Technology’s SDXNS200 high‑temperature combustion ion chromatography analyzer is fully compliant with the requirements for the combustion furnace‑ion chromatography (C‑IC) system specified in ISO 20999:2026 and GB/T 31126.3‑2026, and is specifically designed for halogen determination. Key performance advantages include:
Ultra‑high temperature pyrolysis for complete combustion
The system employs high‑temperature pyrolysis technology with a maximum furnace temperature of 1250°C, well above the minimum 1000°C required by the standards. The effective temperature‑controlled zone extends to 14 cm (±20°C), ensuring sufficient combustion and complete pyrolysis of textile samples in an oxygen‑enriched atmosphere, thereby delivering reliable and accurate results.
Full automation and high throughput
The entire process – combustion, absorption, and analysis – is fully automated. The system accommodates up to 49 solid sample positions and 78 liquid sample positions. A single loading enables overnight unattended continuous testing, significantly improving laboratory throughput and efficiency.
Quantification limit far superior to standard requirements
Based on a 50 mg sample mass, the limit of quantification (LOQ) for fluorine is as low as 0.5 mg/kg – an order of magnitude better than the 10 mg/kg required by ISO 20999:2026.
Experiments and Analysis: Spike Recovery Validation
To verify the quantitative accuracy of the SDXNS200 for typical PFAS substances, spike recovery experiments were conducted at five concentration levels using standards of short-chain sulfonate (PFBS, C4) and medium-chain sulfonate (PFHxS, C6).
PFBS spike recovery
Spike recovery experiments for PFBS (perfluorobutanesulfonic acid, C4) were performed on the SDXNS200 at five concentration levels. Results are shown in Table 1.
Table 1 PFBS spike recovery results
| PFBS (mg/L) | Sample volume (mL) | Blank (mg/L) | F mass fraction (%) | Recovery (%) | Average recovery (%) | RSD (%) |
| 7.821 | 0.20 | 0.005 | 57.17 | 100.61 | 99.50 | 1.58 |
| 7.821 | 0.20 | 0.005 | 57.17 | 98.38 | 99.50 | 1.58 |
| 39.105 | 0.05 | 0.005 | 57.17 | 107.25 | 107.25 | 0.56 |
| 39.105 | 0.05 | 0.005 | 57.17 | 106.86 | 107.25 | 0.56 |
| 78.21 | 0.20 | 0.005 | 57.17 | 95.85 | 96.70 | 1.23 |
| 78.21 | 0.20 | 0.005 | 57.17 | 97.59 | 96.70 | 1.23 |
| 391.05 | 0.20 | 0.005 | 57.17 | 98.78 | 98.63 | 0.21 |
| 391.05 | 0.20 | 0.005 | 57.17 | 98.48 | 98.63 | 0.21 |
| 782.10 | 0.05 | 0.005 | 57.17 | 104.21 | 102.90 | 1.86 |
| 782.10 | 0.05 | 0.005 | 57.17 | 101.58 | 102.90 | 1.86 |
The results show that average spike recoveries at five concentration levels ranged from 96.70% to 107.20%, with RSDs between 0.21% and 1.58%. This demonstrates that the instrument provides accurate recoveries for PFBS across a wide concentration gradient – even over more than two orders of magnitude (7.8-782 mg/L) – with highly consistent fluoride ion response. The system exhibits excellent quantitative accuracy for short-chain sulfonate PFAS.
PFHxS spike recovery
Spike recovery experiments for PFHxS (perfluorohexanesulfonic acid, C6) were conducted on the SDXNS200 at five concentration levels. Results are shown in Table 2.
Table 2 PFHxS spike recovery results
| PFHxS (mg/L) | Sample Volume (mL) | Blank (mg/L) | F mass fraction (%) | Recovery (%) | Average Recovery (%) | RSD(%) |
| 8.296 | 0.20 | 0.005 | 61.88 | 99.28 | 101.33 | 2.90 |
| 8.296 | 0.20 | 0.005 | 61.88 | 103.38 | 101.33 | 2.90 |
| 41.48 | 0.10 | 0.005 | 61.88 | 97.38 | 97.12 | 0.37 |
| 41.48 | 0.10 | 0.005 | 61.88 | 96.86 | 97.12 | 0.37 |
| 82.96 | 0.20 | 0.005 | 61.88 | 97.60 | 98.32 | 1.02 |
| 82.96 | 0.20 | 0.005 | 61.88 | 99.04 | 98.32 | 1.02 |
| 414.80 | 0.10 | 0.005 | 61.88 | 101.68 | 102.21 | 0.57 |
| 414.80 | 0.10 | 0.005 | 61.88 | 102.74 | 102.21 | 0.57 |
| 829.60 | 0.05 | 0.005 | 61.88 | 107.90 | 107.95 | 0.06 |
| 829.60 | 0.05 | 0.005 | 61.88 | 107.99 | 107.95 | 0.06 |
The results show that average spike recoveries at five concentration levels ranged from 97.12% to 107.95%, with RSDs between 0.06% and 2.90%. This confirms that the instrument provides accurate recoveries for PFHxS across varying concentrations and delivers stable, reliable quantification for medium‑chain sulfonate PFAS.
Seize the Opportunity of New Standards and Gain a Head Start in International Trade
The successive release of ISO 20999:2026 and GB/T 31126.3-2026 signals an impending upgrade in compliance requirements for global textile trade. Establishing testing capabilities aligned with the new standards ahead of competitors is the key to gaining advantages in export compliance, quality control, and brand trust.
Sundy Technology’s SDXNS200 high-temperature combustion ion chromatography analyzer has been extensively validated for halogen and sulfur determination in textiles, petrochemicals, liquid crystal materials, ores, wafers, and printed circuit boards. Its non-targeted screening capability effectively compensates for the risk of false negatives associated with LC-MS/MS targeted analysis due to insufficient standard coverage. The method also conforms to internationally recognized total fluorine standards such as EN 14582 and ASTM D7359, and is suitable for PFAS screening under OEKO-TEX® and other ecological textile certification schemes.
The SDXNS200 empowers your laboratory to seamlessly address both ISO 20999:2026 and GB/T 31126.3-2026 in a single solution, confidently navigating the compliance challenges of textile exports and proactively overcoming green trade barriers.
