Objectives

In the current study, an analytical technique has been optimized for the analysis of disinfection by-products (perchlorate (ClO₄⁻), bromate (BrO₃⁻), nitrate (NO₃⁻), nitrite and sulfite (SO₃^2–) in drinking water obtained from spring, well and tap water (desalinated) sources.

Methods

The ultra-performance liquid chromatography-electrospray ionization mass spectrometry (UPLC-ESI/MS) conditions have been optimized for oxyhalides ClO₄⁻ (isotopes, ³⁷ClO₄⁻ and ³⁵ClO₄⁻) and BrO₃⁻ (isotopes, ⁸¹BrO₃⁻ and ⁷⁹BrO₃⁻), and inorganic anions NO₃⁻, NO₂⁻ and SO₃^2–. Separation was achieved by BEH C₁₈ column with methanol (75%) and water (24.99%, HCOOH 0.01%) mobile phase at flow rate 0.2 mL/min.

Results

The analysis was carried out in <1 min with excellent coefficient of determination, (R² > 0.995–0.999), limit of detection (0.016–0.043 µg/L), limit of quantification (0.051–0.104 µg/L) and precision (repeatability, 1.54–2.28% and reproducibility, 3.13–4.08%) in terms of RSD%. The method was successfully applied, and the amounts of ³⁵ClO₄⁻ (5.33–22.64 µg/L), ⁸¹BrO₃⁻ (7.52–16.73 µg/L), NO₃⁻ (5.42–12.14 mg/L), NO₂⁻ (1.08–4.37 mg/L) and SO₃^2– (6.84–32.45 mg/L) were identified in spring water, whereas well and tap water contained ³⁵ClO₄⁻ (4.20–21.33 µg/L), ⁸¹BrO₃⁻ (8.05–15.13 µg/L), NO₃⁻ (1.27–16.11 mg/L), NO₂⁻ (0.43–10.77 mg/L) and SO₃^2– (7.14–36.10 mg/L), and ³⁵ClO₄⁻ (0.89–7.37 µg/L), ⁸¹BrO₃⁻ (5.15–14.68 µg/L), NO₃⁻ (1.12–6.33 mg/L), NO₂⁻ (0.67–3.95 mg/L) and SO₃^2– (5.40–23.26 mg/L), respectively.

Conclusions

The levels of ³⁵ClO₄⁻, ⁸¹BrO₃⁻, NO₃^−, NO₂⁻ and SO₃^2– were found beyond the maximum contaminant levels and drinking water equivalent levels regulated by the Environmental Protection Agency, respectively. The outcomes also revealed that comparatively tap water produced lower levels of these contaminants especially in the cities with low population densities. In addition, the geographical site would be helpful to categorize the tap water samples.

中文翻译：

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UPLC-ESI / MS分析从泉水，井水和自来水（淡化水）获得的微滤饮用水中的消毒副产物（高氯酸盐，溴酸盐，硝酸盐，亚硝酸盐和亚硫酸盐）

目标

在目前的研究中，一种分析技术已为副产物（高氯酸盐（CLO消毒的分析而优化的₄ ^- ），溴（BRO ₃ ^- ），硝酸根（NO ₃ ^- ），亚硝酸盐和亚硫酸盐（SO ₃ ^2-）从泉水，井水和自来水（淡化水）获得的饮用水中。

方法

超高效液相色谱-电喷雾电离质谱（UPLC-ESI / MS）的条件已为卤氧化物CLO优化₄ ^- （同位素，³⁷ CLO ₄ ^-和³⁵ CLO ₄ ^- ）和的BrO ₃ ^- （同位素，⁸¹的BrO ₃ ^-和⁷⁹的BrO ₃ ^- ），和无机阴离子NO ₃ ^-，NO ₂ ^-和SO ₃ ^2-。通过BEH C ₁₈实现分离 流动相为甲醇（75％）和水（24.99％，HCOOH 0.01％）的硅胶柱，流速为0.2 mL / min。

结果

分析在<1分钟内完成，具有极好的测定系数（R ²  > 0.995-0.999），检出限（0.016-0.043 µg / L），定量限（0.051-0.104 µg / L）和精密度（以RSD％计，可重复性为1.54–2.28％，可重复性为3.13–4.08％。该方法已成功应用，和的量³⁵ CLO ₄ ^-（5.33-22.64微克/升），⁸¹的BrO ₃ ^-（7.52-16.73微克/升），NO ₃ ^-（5.42-12.14毫克/升），NO ₂ ⁻在泉水中鉴定出（1.08–4.37 mg / L）和SO ₃ ^2–（6.84–32.45 mg / L），而井水和自来水中含有³⁵ ClO₄ ⁻（4.20–21.33 µg / L），⁸¹ BrO ₃ ⁻（8.05–15.13 µg / L），NO ₃ ⁻（1.27–16.11 mg / L），NO ₂ ⁻（0.43–10.77 mg / L）和SO ₃ ^2-（7.14–36.10 mg / L）和³⁵ ClO ₄ ⁻（0.89–7.37 µg / L），⁸¹ BrO ₃ ⁻（5.15–14.68 µg / L），NO ₃ ⁻（1.12–6.33 mg / L）， NO ₂ ⁻（0.67–3.95 mg / L）和SO ₃ ^2–（5.40–23.26 mg / L）。

结论

水平³⁵ CLO ₄ ^- ，⁸¹的BrO ₃ ^-，NO ₃ ^{- ，} NO ₂ ^-和SO ₃ ^2-，发现超出最大污染物水平和饮用水等效水平由环境保护局，分别调节。结果还表明，相对而言，自来水产生的这些污染物水平较低，尤其是在人口密度较低的城市。另外，该地理位置将有助于对自来水样品进行分类。