Scholarlink

<p>Residual inorganic ions in automated online solid-phase extraction (SPE) workflows can alter electrospray ionization and bias LC–MS/MS quantification of perfluoroalkyl substances (PFAS) in environmental waters. We evaluated the influence of modest salt concentration (10–30&#xa0;mg/L NaCl or CaCl<sub>2</sub>) on the PFAS analytical response using an online SPE–LC–MS/MS system in negative ESI-MRM (Electrospray Ionization-Multiple Reaction Monitoring) mode. PFBA (50&#xa0;ng/L) was non-detectable under salt-free conditions but produced well-defined peaks after salt addition, with detection limits improving to 0.17–0.22&#xa0;ng/L (LOD) and 0.57–0.74&#xa0;ng/L (LOQ) at 20–30&#xa0;mg/L of NaCl and CaCl<sub>2</sub>. The isotopically labeled internal standard remained stable across conditions, but the PFBA/<sup>13</sup>C<sub>4</sub>-PFBA area ratio increased from 1.67 to 1.89, demonstrating incomplete compensation for salt-dependent response changes by isotope dilution. A matrix effect assessment across the full PFAS target list revealed a wide range from − 74% to + 1005%, with short-chain compounds exhibiting the strongest enhancements (up to tenfold for PFPeA) and longer-chain PFAS showing weaker or negative effects. NaCl amplified chain length-dependent contrast more strongly than CaCl<sub>2</sub> did, producing divergent responses, particularly for C<sub>8</sub>–C<sub>9</sub> compounds. These findings demonstrate that the environmentally relevant salt concentrations substantially alter PFAS response patterns in automated online SPE–LC–MS/MS systems, with implications for method validation and data interpretation. The ionic composition should be explicitly considered when quantifying PFAS in water matrices with varying ionic composition, particularly for short-chain compounds where internal standardization provides incomplete correction.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Salt-induced matrix effects on PFAS quantification in online SPE–LC–MS/MS analysis

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年8月3日

查看全文
  • Aleum Lee,
  • Soo Min Song,
  • Hee Sun Moon,
  • Sung Pil Hyun

摘要

Residual inorganic ions in automated online solid-phase extraction (SPE) workflows can alter electrospray ionization and bias LC–MS/MS quantification of perfluoroalkyl substances (PFAS) in environmental waters. We evaluated the influence of modest salt concentration (10–30 mg/L NaCl or CaCl2) on the PFAS analytical response using an online SPE–LC–MS/MS system in negative ESI-MRM (Electrospray Ionization-Multiple Reaction Monitoring) mode. PFBA (50 ng/L) was non-detectable under salt-free conditions but produced well-defined peaks after salt addition, with detection limits improving to 0.17–0.22 ng/L (LOD) and 0.57–0.74 ng/L (LOQ) at 20–30 mg/L of NaCl and CaCl2. The isotopically labeled internal standard remained stable across conditions, but the PFBA/13C4-PFBA area ratio increased from 1.67 to 1.89, demonstrating incomplete compensation for salt-dependent response changes by isotope dilution. A matrix effect assessment across the full PFAS target list revealed a wide range from − 74% to + 1005%, with short-chain compounds exhibiting the strongest enhancements (up to tenfold for PFPeA) and longer-chain PFAS showing weaker or negative effects. NaCl amplified chain length-dependent contrast more strongly than CaCl2 did, producing divergent responses, particularly for C8–C9 compounds. These findings demonstrate that the environmentally relevant salt concentrations substantially alter PFAS response patterns in automated online SPE–LC–MS/MS systems, with implications for method validation and data interpretation. The ionic composition should be explicitly considered when quantifying PFAS in water matrices with varying ionic composition, particularly for short-chain compounds where internal standardization provides incomplete correction.

Graphical Abstract