应用笔记

乳制品中超短链及长链PFAS的综合分析

08 Jun 2026

核心看点

  • 简单、高效的样品前处理流程,可最大限度减少污染并提高回收率。
  • 惰性色谱柱结合独特的极性嵌入型固定相,配合成熟的方法条件,可对超短链、短链、长链及替代型 PFAS 进行同时分析,提供准确、稳定的结果。
  • 经验证适用于多种液态乳样品中 PFAS 污染的综合评估。

摘要

要全面评估 PFAS 污染,必须将超短链 PFAS 与短链、长链及替代型 PFAS 一并纳入分析方法中。本文建立的样品前处理与 LC-MS/MS 工作流程,实现了对不同牛奶基质中多种 PFAS 的定量监测,包括超短链在内的多样化的PFAS分析物。该方法基于线性、准确度和重复性参数进行了评估,随后应用于多种乳制品牛奶、植物奶和婴儿配方奶的实际样品分析。

引言

超短链(USC)全氟和多氟烷基物质(PFAS)是碳链长度短于C4的高极性化合物(见图1),它们在水生环境中普遍存在。由于其广泛分布,人们越来越担心它们对食品(尤其是供婴幼儿食用的即食液态奶制品)造成污染的可能性。虽然目前已有有效的方法用于分析奶样中的长链PFAS [1],但要全面评估PFAS污染情况,将这些超短链化合物纳入检测范围至关重要。

由于牛奶基质复杂,含有蛋白质、脂肪及其他可能干扰检测的成分,分析牛奶中的 PFAS 面临独特挑战。超短链 PFAS 及其他较短链化合物尤其难以分析,因为传统的多步样品前处理方法可能引入背景 PFAS 污染,或导致目标分析物回收率偏低。本研究开发并优化了一套包含蛋白质沉淀、提取液吹干和复溶的样品前处理流程,以实现对所有分析物的有效提取与定量。除样品前处理方面的挑战外,超短链 PFAS 的高极性也给PFAS 分析中常规色谱操作带来显著困难,主要表现为色谱保留不足。本文开发的方法采用惰性涂层、极性嵌入式反相液相色谱柱,以改善保留并提高灵敏度。

该样品前处理流程与色谱方法相结合,构建了一套简单、可靠的工作流程,可在多种牛奶基质中同时分析 C1 至 C14 全氟烷基羧酸和磺酸以及其他类别的 PFAS。方法验证使用了三种不同类型的乳制品(牛奶、植物奶和婴儿配方奶),以确认该流程适用于检测 41 种 PFAS。此外,该方法还在多种实际奶制品中进行了测试,证明其能够有效地对不同奶制品中的 PFAS 污染进行综合分析。

图 1: 超短链 PFAS(C1 至 C3)的结构
PFAS chemical structures

实验部分

超短链 PFAS 背景污染的评估

鉴于超短链 PFAS 在水体系中广泛存在,确保实验室试剂和耗材的洁净度对于准确分析至关重要。其中,TFA 的背景污染尤为令人担忧,因为它可能存在于溶剂、试剂及常用实验室耗材中。通过大量测试,本研究筛选出了最洁净的水、乙腈和甲醇。值得注意的是,用作流动相的不同来源的水相会导致 TFA 检测信号出现显著差异,因此本实验选用了超纯水以确保最佳灵敏度。同样,对用于标准品和样品前处理的各种移液器吸头、HPLC 样品瓶和离心管进行了污染评估,从而选出最洁净的耗材,以保证结果的可靠性。

标准品与样品前处理

校准标准溶液(500 µL)在聚丙烯样品瓶中配制,采用 1:1 的反渗透水与乙腈混合溶液,浓度范围为 4 至 2500 ng/L。使用 18 种稳定同位素标记的 PFAS 作为定量内标(QIS)(表 I)。向每份标准溶液中加入 2.5 µL QIS 工作溶液(各同位素浓度为 10 ng/mL)。将乳样品(0.5 g)称量至 15 mL 聚丙烯离心管中,加入 2.5 µL 10 ng/mL 的 QIS 工作溶液,充分混匀,再加入 1.5 mL 乙腈涡旋 2 分钟进行提取。随后以 4000 rpm 离心,将上清液转移至新的 15 mL 离心管中,在 50 °C 水浴中用缓和氮气吹干。吹干后使用 0.5 mL 1:1 的水:乙腈复溶,涡旋 2 分钟后再次以 4000 rpm 离心。最终上清液转移至聚丙烯样品瓶中进行 LC-MS/MS 分析。

方法准确度与精密度的评估

为证明所建立的工作流程可应用于各种奶制品,使用了三种即食奶制品——全脂牛奶、杏仁奶和婴儿配方奶——来评估方法的准确度和重复性。由于杏仁奶消费广泛,故选其代表植物奶。这些乳样品以 0.010、0.025、0.050、0.10 和 0.25 µg/kg 的浓度加标天然分析物,同时加入同位素标记的 13C-TFA 作为 TFA 回收率测定的替代物。按照上述样品前处理流程处理后,这些浓度在最终样品溶液中分别对应 10、25、50、100 和 250 ng/L。三种乳样品中均检测到本底 PFAS,在计算加标样品浓度时减去其浓度以确定回收率。表 I 列出了用于定量的 QIS 与各分析物的配对关系。由于基质效应存在差异,杏仁奶中的部分分析物需采用替代 QIS 以获得更准确的定量结果。

分析条件

将超短链 PFAS 及相关化合物纳入同一分析方案,分析采用 LC-MS/MS,使用 Waters ACQUITY UPLC I-Class 液相色谱仪和 Xevo TQ-S 三重四极杆质谱仪,按下述条件进行。各 PFAS 的离子对通道(MRM)、质谱参数及用于定量的内标见表 I。采用 Ultra IBD 色谱柱(150 × 2.1 mm,3.0 µm)作为延迟柱,以更有效地去除来自仪器和流动相的背景污染。尽管标准 C18 PFAS 延迟柱通常已足够,但当其与 Ultra IBD Inert 分析柱配合使用时,无法在背景污染物与目标分析物之间提供可接受的分离效果。

色谱柱:
– 分析柱: Ultra IBD Inert, 3.0 µm, 100 x 2.1 mm (cat.# 9175312-T)
– 延迟柱: Ultra IBD, 3.0 µm, 150 x 2.1 mm (cat.# 9175362)
进样体积: 5 µL
流动相 A: 水中含 5 mM 甲酸铵、0.1% 甲酸
流动相 B: 乙腈
流速: 0.4 mL/min
温度: 40 °C
梯度:  
时间 (min) %B
0.00                  45
7.00                  95
11.00                95
11.01                45
13.00                45
离子模式: Negative ESI
模式: Scheduled MRM

表 I: MS/MS 参数与内标

化合物保留时间 (min)母离子子离子a锥孔电压 (V)碰撞能量 (V)QIS
目标分析物
全氟烷基羧酸
Trifluoroacetic acid (TFA) 1.60 113.03 [M-H]- 69.01 10 10 13C2-TFA
Perfluoropropanoic acid (PFPrA) 2.21 162.97 [M-H]- 119.02 10 8 13C3-PFPrA
Perfluorobutanoic acid (PFBA) 2.86 213.03 [M-H]- 168.98 14 8 13C4-PFBA
Perfluoropentanoic acid (PFPeA) 3.64 262.97 [M-H]- 218.97 2 6 13C5-PFPeA
Perfluorohexanoic acid (PFHxA) 4.41 313.10 [M-H]- 268.97/118.99 2 8/20 13C5-PFHxA
Perfluoroheptanoic acid (PFHpA) 5.15 363.16 [M-H]- 319.09/169.06 8 10/18 13C4-PFHpA
Perfluorooctanoic acid (PFOA) 5.84 413.10 [M-H]- 368.96/168.90 2 10/16 13C8-PFOA
Perfluorononanoic acid (PFNA) 6.48 463.10 [M-H]- 419.01/219.02 4 10/16 13C9PFNA
Perfluorodecanoic acid (PFDA) 7.08 513.17 [M-H]- 469.16/219.06 4 12/16 13C6-PFDA
Perfluoroundecanoic acid (PFUnA) 7.65 563.23 [M-H]- 519.24/269.07 6 12/18 13C7-PFUnA
Perfluorododecanoic acid (PFDoA) 8.26 613.23 [M-H]- 569.19/169.06 8 12/26 13C2-PFDoA
Perfluorotridecanoic acid (PFTrDA) 8.94 663.23 [M-H]- 619.21/169.06 8 14/28 13C2-PFTeDA
Perfluorotetradecanoic acid (PFTeDA) 9.75 712.67 [M-H]- 668.69/168.94 10 12/26 13C2-PFTeDA
全氟烷基磺酸
Trifluoromethanesulfonic acid (TFMS) 1.98 148.97 [M-H]- 79.93/98.92 62 18/18 13C3-PFBS
Perfluoroethanesulfonic acid (PFEtS) 2.62 198.90 [M-H]- 79.92/98.91 38 22/22 13C4-PFBA
Perfluoropropanesulfonic acid (PFPrS) 3.30 248.97 [M-H]- 79.92/98.91 2 24/24 13C5-PFPeA
Perfluorobutanesulfonic acid (PFBS) 3.96 298.97 [M-H]- 79.97/98.89 2 26/26 13C3-PFBS
Perfluoropentanesulfonic acid (PFPeS) 4.59 349.10 [M-H]- 79.98/98.98 6 32/30 13C5-PFHxA / 13C8-PFOSb
Perfluorohexanesulfonic acid (PFHxS) 5.17 398.90 [M-H]- 79.97/98.89 56 32/34 13C3-PFHxS
Perfluoroheptanesulfonic acid (PFHpS) 5.70 449.17 [M-H]- 79.98/98.97 4 42/38 13C8-PFOA
Perfluorooctanesulfonic acid (PFOS) 6.19 499.03 [M-H]- 79.92/98.90 8 40/40 13C8-PFOS
Perfluorononanesulfonic acid (PFNS) 6.65 549.10 [M-H]- 79.92/98.83 12 42/40 13C8-PFOS
Perfluorodecanesulfonic acid (PFDS) 7.06 599.17 [M-H]- 79.98/98.83 8 44/46 13C8-PFOS / 13C2-PFDoAb
Perfluoroundecanesulfonic acid (PFUdS) 7.43 648.73 [M-H]- 79.94/98.94 38 50/44 13C8-PFOS / 13C2-PFDoAb
Perfluorododecanesulfonic acid (PFDoS) 7.77 698.77 [M-H]- 79.95/98.94 10 60/44 13C8-PFOS / 13C2-PFDoAb
Perfluorotridecanesulfonic acid (PFTrDS) 8.08 748.73 [M-H]- 79.94/98.94 8 76/52 13C8-PFOS / 13C2-PFDoAb
氟调聚物磺酸
1H,1H,2H,2H-Perfluorohexane sulfonic acid (4:2 FTS) 3.92 327.10 [M-H]- 307.08/80.83 50 18/24 13C4-PFBA / 13C5-PFHxAb
1H,1H,2H,2H-Perfluorooctane sulfonic acid (6:2 FTS) 5.57 427.17 [M-H]- 407.18/80.71 2 22/32 13C8-PFOA
1H,1H,2H,2H-Perfluorodecane sulfonic acid (8:2 FTS) 7.07 527.17 [M-H]- 507.16/80.83 66 26/32 13C3-PFHxS / d5-NEtFOSAAb
全氟烷基磺酰胺
Perfluorooctanesulfonamide (FOSA) 4.01 498.17 [M-H]- 77.97/477.76 8 28/26 13C8-FOSA
全氟烷基磺酰胺基乙酸
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) 6.40 570.20 [M-H]- 419.17/483.16 46 20/14 d3-NMeFOSAA
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) 6.52 584.20 [M-H]- 419.18/483.11 6 20/16 d5-NEtFOSAA
全氟和多氟醚羧酸
Perfluoro-3-methoxypropanoic acid (PFMPA) 3.05 228.93 [M-H]- 84.97/198.94 10 10/14 13C4-PFBA
Perfluoro-4-methoxybutanoic acid (PFMBA) 3.76 278.87 [M-H]- 84.96/234.93 8 10/6 13C5-PFPeA
Hexafluoropropylene oxide dimer acid (HFPO-DA) 4.37 285.03 [M-COOH]- 169.02/185.02 2 6/16 13C5-PFHxA
4,8-Dioxa-3H-perfluorononanoic acid (ADONA) 4.71 376.90 [M-H]- 250.93/84.97 22 12/26 13C4-PFHpA
全氟和多氟醚磺酸
Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA) 4.09 314.83 [M-H]- 134.94/83.01 4 22/16 13C3-PFBS
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS) 6.20 530.78 [M-H]- 350.85/82.96 12 26/24 13C8-PFOA
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) 6.92 630.78 [M-H]- 450.80/82.95 8 26/32 13C8-PFOS
Capstone 表面活性剂
Capstone A 0.95 527.08 [M-H]- 507.02/181.06 2 10/12 13C2-TFA / 13C3-PFPrAb
Capstone B 1.90 569.07 [M-H]- 549.01/445.96 32 12/16 13C3-PFPrA
定量内标
13C2-TFA 2.69 114.90 [M-H]- 69.95 14 8
13C3-PFPrA 2.69 165.97 [M-H]- 120.96 10 11
13C4-PFBA 3.27 217.03 [M-H]- 171.98 2 8
13C5-PFPeA 3.94 267.97 [M-H]- 222.99 2 6
13C5-PFHxA 4.59 318.03 [M-H]- 272.93 2 7
13C4-PFHpA 5.24 366.90 [M-H]- 321.93 2 10
13C8-PFOA 5.86 420.97 [M-H]- 375.94 2 10
13C9PFNA 5.86 471.97 [M-H]- 426.87 4 12
13C6-PFDA 7.03 518.90 [M-H]- 473.87 4 13
13C7-PFUnA 7.60 569.90 [M-H]- 524.87 2 12
13C2-PFDoA 8.23 614.84 [M-H]- 569.87 2 12
13C2-PFTeDA 9.83 714.78 [M-H]- 669.80 8 14
13C3-PFBS 3.97 301.97 [M-H]- 79.97 2 28
13C3-PFHxS 5.01 401.90 [M-H]- 79.97 2 36
13C8-PFOS 5.96 506.84 [M-H]- 79.97 4 42
13C8-FOSA 3.36 505.91 [M-H]- 77.95 4 32
d3-NMeFOSAA 6.44 572.90 [M-H]- 418.91 50 18
d5-NEtFOSAA 6.56 588.97 [M-H]- 418.86 48 20
ᵃ 定量离子 / 定性离子。
ᵇ 用于杏仁奶中的定量。

结果与讨论

色谱性能

此前已开发出相关分析方法,将超短链 PFAS 纳入用于检测各种水基质 [2] 和人体血液 [3] 中 PFAS 的综合方法。这些方法采用极性嵌入式烷基 Ultra IBD 固定相,以确保对高极性超短链 PFAS 提供足够的保留。此外,研究还表明,惰性涂层 Ultra IBD 色谱柱可显著提高大多数 PFAS 化合物的检测灵敏度 [2],该色谱柱采用经惰性涂层处理的硬件,可防止分析物与色谱柱不锈钢表面发生非特异性相互作用。本研究同样将类似的色谱方法应用于液态奶中的 PFAS 分析。然而,由于液态奶基质的干扰比水基质更强,为获得早出峰化合物的最佳色谱峰形,进样体积控制为 5 μL。

图 2 显示了加标乳样品分析的典型色谱图。除依据 EURL 指南 [4] 评估的 28 种 PFAS 化合物外,本分析通过纳入超短链 PFAS、氟调聚物磺酸以及更广泛的替代型 PFAS 化合物,扩展至 41 种分析物。EURL 指南指出,胆汁酸(如牛磺熊去氧胆酸(TUDCA)、牛磺鹅去氧胆酸(TCDCA)和牛磺去氧胆酸(TDCA))在乳样品中可能以高浓度存在,并因其与 PFOS 共享MRM而可能干扰 PFOS 的定量。我们的测试证实,TUDCA、TCDCA 和 TDCA 的保留时间均与 PFOS 不同,从而确保它们不会影响 PFOS 结果的准确性(图 3)。此外,这些胆汁酸的检测灵敏度显著低于 PFOS(约低 100 倍),且在本研究分析的最终乳样品溶液中均未检出。

图 2: 0.1 µg/kg 加标全脂牛奶样品的分析(LC_FS0563)
Integrating Ultrashort-Chain Compounds into Comprehensive PFAS Analysis in Liquid Milk

LC_FS0563

Peaks

PeakstR (min)Precursor IonQuantification IonConfirmation Ion
1.Capstone A0.95527.08507.02181.06
2.Trifluoroacetic acid (TFA)1.60113.0369.01
3.13C-Trifluoroacetic acid (13C-TFA)1.60114.0369.03
4.Capstone B 1.90569.07549.01445.96
5.Trifluoromethanesulfonic acid (TFMS)1.98148.9779.9398.92
6.Perfluoropropanoic acid (PFPrA)2.21162.97119.02
7.Perfluoroethanesulfonic acid (PFEtS)2.62198.9079.9298.91
8.Perfluoro-3-methoxypropanoic acid (PFMPA)3.05228.9384.97198.94
9.Perfluoropropanesulfonic acid (PFPrS)3.30248.9779.9298.91
10.Perfluoropentanoic acid (PFPeA)3.64262.97218.97
11.Perfluoro-4-methoxybutanoic acid (PFMBA)3.76278.8784.96234.93
12.1H,1H,2H,2H-Perfluorohexane sulfonic acid (4:2 FTS)3.92327.10307.0880.83
13.Perfluorobutanesulfonic acid (PFBS)3.96298.9779.9798.89
14.Perfluorooctanesulfonamide (FOSA)4.01498.1777.97477.76
15.Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)4.09314.83134.9483.01
16.Hexafluoropropylene oxide dimer acid (HFPO-DA)4.37285.03169.02185.02
17.Perfluorohexanoic acid (PFHxA)4.41313.10268.97118.99
18.Perfluoropentanesulfonic acid (PFPeS)4.59349.1079.9898.98
19.4,8-Dioxa-3H-perfluorononanoic acid (ADONA)4.71376.90250.9384.97
20.Perfluoroheptanoic acid (PFHpA)5.15363.16319.09169.06
PeakstR (min)Precursor IonQuantification IonConfirmation Ion
21.Perfluorohexanesulfonic acid (PFHxS)5.17398.9079.9798.89
22.1H,1H,2H,2H-Perfluorooctane sulfonic acid (6:2 FTS)5.57427.17407.1880.71
23.Perfluoroheptanesulfonic acid (PFHpS)5.70449.1779.9898.97
24.Perfluorooctanoic acid (PFOA)5.84413.10368.96168.90
25.Perfluorooctanesulfonic acid (PFOS)6.19499.0379.9298.90
26.9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)6.20530.78350.8582.96
27.N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)6.40570.20419.17483.16
28.Perfluorononanoic acid (PFNA)6.48463.10419.01219.02
29.N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)6.52584.20419.18483.11
30.Perfluorononanesulfonic acid (PFNS)6.65549.1079.9298.83
31.11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)6.92630.78450.8082.95
32.Perfluorodecanesulfonic acid (PFDS)7.06599.1779.9898.83
33.1H,1H,2H,2H-Perfluorodecane sulfonic acid (8:2 FTS)7.07527.17507.1680.83
34.Perfluorodecanoic acid (PFDA)7.08513.17469.16219.06
35.Perfluoroundecanesulfonic acid (PFUdS)7.43648.7379.9498.94
36.Perfluoroundecanoic acid (PFUnA)7.65563.23519.24269.07
37.Perfluorododecanesulfonic acid (PFDoS)7.77698.7779.9598.94
38.Perfluorotridecanesulfonic acid (PFTrDS)8.08748.7379.9498.94
39.Perfluorododecanoic acid (PFDoA)8.26613.23569.19169.06
40.Perfluorotridecanoic acid (PFTrDA)8.94663.23619.21169.06
41.Perfluorotetradecanoic acid (PFTeDA)9.75712.67668.69168.94

Conditions

ColumnUltra IBD Inert (cat.# 9175312-T)
Dimensions:100 mm x 2.1 mm ID
Particle Size:3 µm
Pore Size:100 Å
Temp.:40 °C
Standard/Sample
PFAS 28 calibration standard (cat.# 30734)
Other standards were obtained externally
Diluent:50:50 water:acetonitrile
Conc.: Whole milk fortified at 0.1 μg/kg
Inj. Vol.:5 µL
Mobile Phase
A:Water, 5mM ammonium formate, 0.1% formic acid
B:Acetonitrile
Time (min)Flow (mL/min)%A%B
0.000.45545
7.000.4595
11.000.4595
11.010.45545
13.000.45545
Max Pressure:540 bar
DetectorWaters Xevo TQ-S
Ion Source:Waters Zspray ESI
Ion Mode:ESI-
Mode:MRM
InstrumentWaters ACQUITY UPLC I-Class
Sample PreparationMilk samples (0.5 g) were weighed into 15 mL polypropylene centrifuge tubes, spiked with analytes at 0.1 μg/kg, thoroughly mixed, and extracted with 1.5 mL of acetonitrile by vortexing for 2 minutes. The mixture was then centrifuged at 4000 rpm, and the supernatant was transferred to a new 15 mL tube and dried under a gentle nitrogen stream in a 50 °C water bath. The dried residue was reconstituted with 0.5 mL of a 1:1 water:acetonitrile diluent, vortexed for 2 minutes, and centrifuged again at 4000 rpm. The final supernatant was transferred to polypropylene HPLC vials for LC-MS/MS analysis.
NotesThe confirmation ion peaks were not shown in the chromatogram.

An Ultra IBD column (150 x 2.1 mm, 3.0 μm; cat # 9175362) was used as the delay column.


For the chromatograms of perfluoroalkyl carboxylic and sulfonic acids, the peak numbers correspond to the carbon chain lengths of the PFAS compounds.

图 3: PFOS 与潜在干扰胆汁酸的完全色谱分离(LC_FS0565)
Distinct Retention Times Between PFOS and Bile Acids

LC_FS0565

Peaks

PeakstR (min)Conc.
(ng/mL)
Precursor IonConfirmation Ion
1.Tauroursodeoxycholic acid (TUDCA)4.50100499.0379.92
2.Perfluorooctanesulfonic acid (PFOS)6.050.5499.0379.92
3.Taurochenodeoxycholic acid (TCDCA)6.55100499.0379.92
4.Taurodeoxycholic acid (TDCA)6.74100499.0379.92

Conditions

ColumnUltra IBD Inert (cat.# 9175312-T)
Dimensions:100 mm x 2.1 mm ID
Particle Size:3 µm
Pore Size:100 Å
Temp.:40 °C
Standard/SampleIndividual standards were obtained externally.
Diluent:50:50 water:acetonitrile
Inj. Vol.:5 µL
Mobile Phase
A:Water, 5 mM ammonium formate, 0.1% formic acid
B:Acetonitrile
Time (min)Flow (mL/min)%A%B
0.000.45545
7.000.4595
11.000.4595
11.010.45545
13.000.45545
Max Pressure:540 bar
DetectorWaters Xevo TQ-S
Ion Source:Waters Zspray ESI
Ion Mode:ESI-
Mode:MRM
InstrumentWaters ACQUITY UPLC I-Class
Sample PreparationIndividual standards were prepared in 50:50 water:acetonitrile solution in polypropylene HPLC vials.
NotesAn Ultra IBD column (150 x 2.1 mm, 3.0 μm; cat # 9175362) was used as the delay column.

线性

采用二次回归(1/x 加权),所有分析物均表现出可接受的线性,r² > 0.995,偏差 < 30%。校准范围为:TFA 为 20–2500 ng/L;HFPO-DA、capstone A 和 capstone B 为 20–1000 ng/L;其余分析物为 4–1000 ng/L。

准确度与重复性

分别于不同日期开展了 3 批分析,每个加标水平共进行了 9 次平行测定。各基质中每种 PFAS 的平均回收率和相对标准偏差(RSD)见表 II。所有分析物的回收率范围为:全脂牛奶 78.3–119%、杏仁奶 81.6–129%、婴儿配方奶 80.5–118%。%RSD 值均 ≤15%,表明方法重复性令人满意。由于基质抑制较强或检测信号较弱,13C-TFA、PFPrA、FOSA、HFPO-DA、Capstone A、Capstone B 和 PFMPA 在部分或全部 0.01 µg/kg 加标样品中的回收率无法测定。由于特定的基质抑制,Capstone A 在杏仁奶中无法识别和测定。

表 II: 加标乳样品中 PFAS 的准确度与精密度分析

全脂牛奶

平均回收率(RSD,%),n = 9
按加标浓度(µg/kg)
分析物 0.010 0.025 0.050 0.10 0.25
13C-TFA 104 (9.40) 108 (6.19) 111 (7.65) 114 (6.02)
PFPrA 110 (9.22) 108 (9.29) 114 (5.59) 112 (7.55) 119 (4.73)
PFBA 115 (3.43) 104 (6.80) 111 (8.73) 108 (4.26) 112 (3.60)
PFPeA 106 (8.48) 91.3 (8.68) 92.0 (10.0) 97.5 (12.4) 102 (6.73)
PFHxA 108 (4.27) 87.9 (7.77) 92.6 (9.97) 90.9 (10.8) 105 (5.71)
PFHpA 113 (4.65) 93.7 (6.82) 92.1 (8.58) 90.3 (6.51) 103 (9.38)
PFOA 112 (9.69) 91.6 (12.9) 83.3 (11.4) 86.9 (4.64) 103 (10.5)
PFNA 114 (7.32) 102 (7.47) 101 (6.33) 105 (5.50) 110 (4.46)
PFDA 110 (10.7) 86.4 (8.71) 88.8 (8.37) 95.3 (10.8) 103 (9.83)
PFUnA 109 (8.75) 87.3 (11.8) 95.1 (9.90) 95.0 (10.7) 96.4 (13.9)
PFDoA 113 (7.22) 81.7 (8.30) 88.5 (9.97) 93.6 (6.06) 97.5 (15.0)
PFTrDA 113 (8.61) 85.4 (4.62) 86.7 (4.92) 95.2 (9.83) 95.4 (3.12)
PFTeDA 105 (13.5) 78.9 (7.25) 85.1 (12.2) 96.1 (8.25) 98.3 (15.1)
TFMS 112 (7.81) 107 (10.4) 112 (5.96) 82.9 (5.82) 84.6 (7.92)
PFEtS 104 (9.39) 103 (7.51) 105 (7.90) 114 (5.96) 116 (5.55)
PFPrS 95.7 (5.72) 87.6 (7.53) 94.5 (5.08) 91.3 (12.9) 99.7 (7.59)
PFBS 104 (12.7) 95.8 (13.0) 99.1 (9.98) 100 (10.3) 109 (8.59)
PFPeS 102 (9.04) 93.5 (12.4) 90.2 (11.5) 93.8 (14.0) 107 (13.5)
PFHxS 104 (8.83) 90.6 (12.4) 85.2 (8.26) 88.2 (8.90) 108 (10.4)
PFHpS 85.9 (4.54) 85.0 (4.97) 84.6 (8.85) 83.5 (3.94) 97.4 (10.0)
PFOS 109 (6.76) 102 (10.3) 102 (7.83) 93.0 (13.7) 102 (10.5)
PFNS 104 (10.8) 88.4 (11.0) 96.8 (14.1) 86.9 (5.59) 103 (10.4)
PFDS 98.5 (12.7) 91.7 (12.0) 97.3 (13.5) 95.8 (14.3) 106 (7.60)
PFUdS 86.1 (5.93) 93.1 (7.89) 105 (10.9) 91.0 (8.73) 108 (6.82)
PFDoS 116 (3.54) 78.3 (8.12) 101 (7.02) 86.5 (9.40) 102 (9.72)
PFTrDS 95.7 (14.4) 81.0 (2.20) 93.3 (6.78) 91.7 (13.2) 106 (10.5)
4:2 FTS 103 (8.31) 102 (12.1) 102 (10.2) 113 (8.30) 116 (2.94)
6:2 FTS 108 (9.23) 115 (6.07) 96.4 (9.84) 87.9 (10.2) 109 (5.90)
8:2 FTS 92.5 (15.3) 94.2 (12.3) 90.5 (7.92) 83.1 (5.62) 95.0 (8.98)
FOSA 103 (8.53) 88.3 (12.9) 96.3 (13.2) 112 (6.15)
NMeFOSAA 107 (9.71) 86.6 (8.05) 86.1 (8.46) 92.4 (10.7) 98.9 (12.9)
NEtFOSAA 107 (7.37) 94.3 (8.12) 94.8 (10.6) 105 (7.31) 110 (5.73)
PFMPA 86.1 (9.47) 88.4 (8.49) 84.0 (9.50) 85.4 (5.55) 90.4 (7.52)
PFMBA 87.4 (10.3) 98.5 (11.8) 85.8 (8.29) 98.6 (8.80) 102 (5.72)
HFPO-DA 98.7 (13.5) 96.9 (9.14) 88.2 (15.1) 98.6 (14.0)
ADONA 113 (4.56) 87.7 (7.80) 85.9 (7.20) 84.5 (1.90) 91.5 (8.03)
PFEESA 94.1 (10.6) 91.2 (12.4) 98.4 (11.7) 104 (8.42) 110 (7.01)
9Cl-PF3ONS 93.2 (7.90) 80.5 (7.82) 83.7 (5.62) 88.6 (5.48) 97.2 (11.2)
11Cl-PF3OUdS 99.8 (8.00) 82.3 (6.39) 92.4 (9.85) 101 (13.3) 106 (8.15)
Capstone A 85.9 (11.8) 103 (9.31) 111 (5.74) 118 (6.80)
Capstone B 108 (8.60) 99.9 (15.0) 113 (4.46) 118 (2.83)

杏仁奶

平均回收率(RSD,%),n = 9
按加标浓度(µg/kg)
分析物 0.010 0.025 0.050 0.10 0.25
13C-TFA 127 (4.47) 129 (2.78) 125 (7.85) 110 (8.27)
PFPrA 120 (5.45) 115 (6.71) 114 (5.40) 119 (5.62)
PFBA 112 (7.95) 106 (8.08) 103 (8.48) 98.0 (6.45) 101 (14.2)
PFPeA 97.1 (7.51) 101 (10.8) 99.5 (10.8) 92.1 (8.40) 95.4 (7.09)
PFHxA 90.8 (12.2) 111 (10.1) 100 (7.90) 94.0 (6.60) 102 (9.41)
PFHpA 116 (5.79) 98.8 (6.45) 88.9 (5.97) 87.4 (6.15) 94.1 (6.10)
PFOA 109 (7.29) 113 (6.75) 102 (6.76) 109 (3.37) 114 (3.33)
PFNA 88.0 (8.26) 90.0 (7.59) 81.6 (6.43) 84.6 (4.29) 89.7 (7.17)
PFDA 106 (14.3) 95.0 (7.55) 84.7 (5.31) 92.6 (5.61) 94.2 (3.03)
PFUnA 105 (9.34) 93.4 (8.81) 99.1 (11.7) 108 (6.58) 106 (4.40)
PFDoA 115 (4.66) 114 (3.60) 114 (5.06) 119 (2.60) 119 (2.65)
PFTrDA 105 (8.08) 111 (4.47) 116 (6.70) 126 (3.29) 125 (3.64)
PFTeDA 106 (6.29) 112 (3.62) 118 (2.81) 128 (3.46) 128 (3.19)
TFMS 100 (9.22) 107 (7.45) 110 (4.41) 87.9 (5.54) 88.9 (8.59)
PFEtS 115 (6.22) 111 (7.45) 118 (3.40) 112 (6.29) 118 (3.93)
PFPrS 91.9 (8.44) 92.3 (5.94) 100 (8.15) 95.5 (4.92) 98.3 (7.83)
PFBS 112 (6.31) 92.1 (11.8) 98.9 (8.42) 90.1 (7.68) 101 (10.6)
PFPeS 99.7 (13.6) 111 (10.9) 103 (7.36) 100 (10.0) 106 (11.5)
PFHxS 100 (9.16) 95.9 (9.88) 101 (10.4) 111 (6.40) 108 (5.15)
PFHpS 86.9 (6.71) 96.0 (9.84) 84.5 (5.45) 92.1 (3.27) 99.5 (5.34)
PFOS 115 (4.37) 90.3 (10.9) 83.4 (5.20) 83.7 (7.66) 91.3 (8.34)
PFNS 89.6 (12.1) 92.3 (11.3) 82.8 (5.36) 95.0 (6.73) 93.0 (10.6)
PFDS 108 (12.8) 101 (11.6) 110 (5.53) 110 (9.70) 119 (3.14)
PFUdS 93.9 (11.4) 93.8 (9.55) 98.4 (7.86) 115 (1.83) 118 (3.13)
PFDoS 90.3 (7.00) 100 (9.86) 107 (6.95) 118 (2.42) 118 (2.26)
PFTrDS 95.9 (10.9) 94.0 (9.28) 99.6 (6.13) 114 (3.42) 115 (3.09)
4:2 FTS 87.6 (7.37) 108 (7.99) 105 (8.12) 99.7 (8.11) 105 (8.52)
6:2 FTS 113 (6.80) 113 (6.76) 110 (5.34) 105 (6.80) 105 (5.44)
8:2 FTS 118 (3.57) 101 (8.58) 96.4 (7.93) 108 (4.60) 103 (6.98)
FOSA 105 (12.5) 103 (7.55) 107 (6.24) 97.7 (10.6) 109 (5.68)
NMeFOSAA 105 (5.69) 92.2 (13.1) 87.0 (7.11) 91.8 (8.89) 98.0 (8.37)
NEtFOSAA 108 (7.59) 103 (9.82) 88.1 (9.60) 101 (10.5) 104 (6.61)
PFMPA 88.7 (6.82) 93.8 (9.95) 97.8 (13.1) 97.2 (9.27) 109 (5.00)
PFMBA 94.1 (11.1) 90.9 (10.4) 96.1 (9.65) 98.9 (6.79) 107 (6.54)
HFPO-DA 107 (9.78) 103 (10.2) 105 (11.1) 112 (5.38)
ADONA 101 (13.8) 104 (8.18) 88.0 (7.00) 83.8 (7.37) 89.8 (5.29)
PFEESA 103 (13.6) 95.2 (8.88) 97.2 (10.9) 94.9 (7.39) 101 (10.3)
9Cl-PF3ONS 108 (8.15) 96.7 (3.42) 81.7 (3.82) 95.0 (4.48) 94.2 (5.43)
11Cl-PF3OUdS 86.7 (8.10) 92.9 (8.10) 82.9 (2.81) 85.7 (3.71) 84.0 (9.17)
Capstone A
Capstone B 104 (7.55) 95.0 (14.0) 105 (9.55) 92.6 (11.2)

婴儿配方奶

平均回收率(RSD,%),n = 9
按加标浓度(µg/kg)
分析物 0.010 0.025 0.050 0.10 0.25
13C-TFA 95.8 (12.9) 102 (6.25) 110 (10.2) 110 (9.68)
PFPrA 96.6 (8.80) 99.2 (7.87) 92.0 (4.92) 116 (4.05)
PFBA 107 (7.01) 107 (8.41) 108 (4.84) 110 (4.96) 109 (4.42)
PFPeA 93.1 (6.70) 99.7 (9.51) 99.8 (9.22) 88.3 (7.39) 99.3 (6.81)
PFHxA 101 (8.37) 94.5 (10.6) 99.9 (7.70) 98.5 (4.85) 106 (7.37)
PFHpA 94.0 (9.15) 98.6 (8.38) 99.6 (7.19) 97.0 (8.02) 104 (6.90)
PFOA 97.2 (11.7) 102 (10.9) 103 (5.99) 105 (6.93) 110 (3.65)
PFNA 101 (5.60) 97.0 (5.33) 107 (4.99) 110 (5.07) 116 (4.24)
PFDA 91.4 (6.59) 89.9 (6.39) 110 (4.69) 116 (3.48) 113 (1.86)
PFUnA 99.1 (10.8) 86.8 (4.92) 105 (7.70) 116 (3.81) 112 (7.38)
PFDoA 82.7 (3.01) 82.2 (2.66) 96.4 (3.87) 106 (4.87) 106 (4.39)
PFTrDA 86.2 (3.82) 81.5 (1.67) 96.2 (6.82) 96.9 (4.46) 113 (5.98)
PFTeDA 81.8 (4.54) 80.8 (6.32) 89.8 (2.41) 90.1 (3.28) 106 (3.09)
TFMS 110 (7.01) 99.5 (8.05) 99.3 (7.09) 107 (9.75) 106 (10.4)
PFEtS 90.4 (12.1) 94.9 (6.25) 88.8 (5.44) 90.0 (7.63) 96.0 (5.53)
PFPrS 99.4 (9.37) 92.3 (8.05) 97.1 (4.87) 94.4 (7.57) 101 (4.53)
PFBS 101 (12.8) 107 (8.88) 98.2 (11.5) 94.6 (7.03) 109 (11.2)
PFPeS 111 (7.96) 106 (7.55) 108 (8.38) 106 (4.36) 111 (6.12)
PFHxS 85.5 (6.65) 89.1 (12.3) 96.1 (13.3) 96.2 (9.71) 105 (5.29)
PFHpS 87.9 (9.29) 88.0 (4.81) 90.9 (4.84) 89.1 (6.79) 94.4 (3.34)
PFOS 89.2 (9.65) 89.4 (10.7) 112 (7.14) 106 (7.94) 107 (6.53)
PFNS 86.9 (9.81) 82.7 (5.10) 108 (6.65) 107 (10.4) 108 (5.39)
PFDS 87.5 (11.9) 88.9 (9.25) 109 (7.57) 106 (9.44) 105 (8.17)
PFUdS 89.7 (10.2) 84.9 (5.13) 105 (9.17) 95.3 (10.4) 97.1 (6.65)
PFDoS 91.0 (9.86) 81.7 (6.58) 98.6 (10.6) 84.7 (8.43) 89.8 (9.51)
PFTrDS 80.5 (6.95) 83.6 (13.6) 94.6 (8.68) 84.6 (12.2) 93.0 (13.4)
4:2 FTS 101 (10.1) 113 (6.58) 108 (6.31) 112 (4.14) 112 (6.30)
6:2 FTS 111 (7.44) 99.8 (5.59) 110 (9.56) 116 (4.78) 118 (4.57)
8:2 FTS 89.4 (8.88) 86.2 (8.13) 107 (6.72) 117 (4.84) 115 (5.38)
FOSA 88.4 (8.80) 90.0 (7.86) 96.5 (13.6) 99.7 (7.60) 107 (12.2)
NMeFOSAA 89.0 (10.5) 87.9 (9.53) 101 (9.92) 102 (8.70) 103 (6.85)
NEtFOSAA 104 (9.71) 91.4 (9.41) 109 (7.39) 115 (4.19) 115 (4.33)
PFMPA 82.1 (4.74) 82.0 (3.76) 83.1 (4.58) 84.9 (4.63)
PFMBA 88.7 (12.1) 103 (12.5) 96.2 (8.93) 92.3 (9.42) 103 (6.87)
HFPO-DA 94.7 (13.7) 105 (7.55) 101 (5.29) 104 (9.62)
ADONA 117 (3.44) 108 (8.64) 108 (7.27) 104 (7.23) 108 (6.31)
PFEESA 99.7 (10.9) 110 (5.44) 106 (6.32) 100 (8.12) 109 (10.2)
9Cl-PF3ONS 84.8 (5.47) 87.8 (5.83) 83.6 (6.65) 84.4 (3.03) 86.3 (4.58)
11Cl-PF3OUdS 84.2 (7.68) 91.6 (8.41) 106 (5.69) 101 (7.79) 100 (5.06)
Capstone A 89.7 (10.4) 81.9 (7.72) 83.7 (6.37) 88.4 (9.29)
Capstone B 93.8 (11.3) 93.6 (12.4) 107 (11.8) 104 (12.7)

实际样品分析

从当地商店采集 24 个乳品,采用所建立的工作流程评估 PFAS 污染。每个样品均制作双份。结果显示,乳样品中普遍存在 TFA、TFMS、PFBA 和 PFHpA(表 III)。值得注意的是,所有受测豆奶样品均含有高浓度的 PFPrA 和 PFBA。在部分样品中检测到长链化合物,包括 PFOA、PFOS、PFNA、PFDoA 和 PFTeDA。除全氟烷基羧酸和磺酸类物质外,6:2 FTS(一种氟调聚物磺酸化合物)是唯一被检出的其他PFAS,并且它在所有四种婴幼儿配方奶粉样品以及部分其他奶样中均有检出。部分乳样品中的 TFA 浓度显著偏高并超出校准范围,需在提取前对样品进行稀释以获得准确的定量结果。

表 III: 各种乳样品基质中 41 种目标 PFAS 的测定

浓度(µg/kg)
超短链短链长链其他
乳样品 TFA PFPrA TFMS PFBA PFHpA PFOA PFOS PFNA PFDoA PFTeDA 6:2 FTS
乳制品牛奶
Whole Milk #1 2.3 nd 0.0049 nd nd nd nd nd nd nd nd
Whole Milk #2 4.3 0.035 0.065 0.087 0.0093 0.0044 nd nd nd nd nd
Whole Milk #3 4.1 nd <0.0040 0.038 <0.0040 0.0045 nd nd <0.0040 nd 0.011
Whole Milk #4 3.0 nd 0.0052 0.012 <0.0040 nd nd nd nd nd nd
2% Reduced Fat Milk #1 3.5 nd 0.012 0.023 0.0045 0.0094 0.018 <0.0040 <0.0040 <0.0040 0.0043
2% Reduced Fat Milk #2 4.0 nd 0.0052 0.015 nd nd nd nd nd nd nd
Fat-Free Milk #1 3.6 nd 0.0055 0.011 nd nd nd nd nd nd nd
Fat-Free Milk #2 3.4 nd 0.0046 0.010 <0.0040 <0.0040 nd nd nd nd 0.0041
Fat-Free Milk #3 2.4 nd 0.0076 nd nd nd nd nd nd nd nd
植物基奶
Almond Milk #1 1.8 nd 0.0043 0.017 nd nd nd nd nd nd nd
Almond Milk #2 2.2 nd 0.0070 0.021 <0.0040 <0.0040 nd nd <0.0040 nd <0.0040
Almond Milk #3 5.3 nd 0.013 0.039 <0.0040 nd nd nd nd nd nd
Oat Milk #1 7.2 nd 0.027 0.016 <0.0040 0.0052 0.0086 nd nd nd 0.055
Oat Milk #2 11 nd 0.021 0.019 nd nd nd nd nd nd 0.0053
Soy Milk #1 24 0.52 0.016 0.21 <0.0040 nd nd nd nd nd nd
Soy Milk #2 11 0.26 0.013 0.10 <0.0040 nd nd nd nd nd nd
Soy Milk #3 5.6 0.088 0.016 0.069 nd nd nd nd nd nd nd
Coconut Milk #1 1.1 nd 0.0047 0.013 <0.0040 nd nd nd nd nd nd
Coconut Milk #2 1.0 nd 0.0043 nd <0.0040 0.0053 nd nd nd nd 0.0053
婴儿配方奶
Formula #1 1.0 nd <0.0040 nd nd nd nd nd nd nd 0.0064
Formula #2 0.4 nd <0.0040 nd <0.0040 nd nd nd nd nd 0.0074
Formula #3 0.8 nd <0.0040 0.012 <0.0040 <0.0040 nd nd nd nd 0.0050
Formula #4 1.2 nd 0.0069 0.011 <0.0040 0.0050 nd nd nd nd 0.012
nd = 未检出
类别:TFA / PFPrA / TFMS = 超短链;PFBA / PFHpA = 短链;PFOA / PFOS / PFNA / PFDoA / PFTeDA = 长链;6:2 FTS = 其他。

结论

本研究开发了一套简单、稳健的工作流程,用于在各种乳样品基质中进行 PFAS 的综合分析,成功地将超短链 PFAS 与更常分析的化合物一并纳入。优化的样品前处理流程与灵敏的液相方法相结合,实现了对 41 种 PFAS 的有效提取与定量,准确度和重复性均较高。该方法采用了独特的 Ultra IBD Inert 色谱柱,其特点是极性嵌入式烷基固定相和柱管经惰性涂层钝化,可增强对超短链化合物的保留,并最大限度减少分析物相互作用以提高灵敏度。该工作流程成功应用于市售奶制品分析,揭示了不同来源奶制品中 PFAS 污染情况,为食品中 PFAS 风险评估提供了重要参考。研究结果进一步凸显了将超短链 PFAS 纳入常规食品监测体系的重要性,并为未来食品安全研究与法规监管提供了可靠的技术支持。

参考文献

  1. J. York, Analysis of PFAS in milk by LC-MS/MS, Application note, FSAN4338-UNV, Restek Corporation, 2024. https://www.restek.com/articles/analysis-of-pfas-in-milk-by-lc-ms-ms
  2. S.H. Liang, Incorporating ultrashort-chain compounds into comprehensive PFAS analysis in waters, Application note, EVAN4402-UNV, Restek Corporation, 2025. https://www.restek.com/articles/incorporating-ultrashort-chain-compounds-into-comprehensive-pfas-analysis-in-waters
  3. S.H. Liang, J. Steimling, C1-C10 PFAS analysis in human plasma and serum, Application note, CFAN4273A-UNV, Restek Corporation, 2025. https://www.restek.com/articles/c1-c10-pfas-analysis-in-human-plasma-and-serum
  4. European Union Reference Laboratory for halogenated POPs in Feed and Food. Guidance Document on Analytical Parameters for the Determination of Per- and Polyfluoroalkyl Substances (PFAS) in Food and Feed. Version 1.2. May 2022. https://eurl-pops.eu/news/guidance-document-pfas/guidance-document-pfas

相关产品


Ultra IBD Inert, 3 µm, 100 x 2.1 mm HPLC Column
Ultra IBD, 3 µm, 150 x 2.1 mm HPLC Column
PFAS 28 Calibration Standard, 1 µg/mL, Methanol (1 mM KOH), 1 mL/ampul
Empty Centrifuge Tubes, 50 mL, Polypropylene w/Cap, 50-pk.

作者

  • Shun-Hsin Liang, PhD

    Shun-Hsin is a senior principal scientist in LC Solutions at Restek. He received his bachelor’s degree from the National Taiwan University in 1988 and obtained his PhD from Michigan State University in 1996. He performed postdoctoral research at the University of Michigan from 1996 to 2000 for oncology studies. In 2001, he was appointed as research faculty at The Pennsylvania State University and focused on molecular toxicology research. In 2006, he joined MPI Research Inc. as a senior research scientist and was a study director for GLP analytical projects. In 2013, Dr. Liang joined the LC Solutions department at Restek and specialized in developing application methods across the fields of environmental, food safety, and life sciences.

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FSAN5396-CN
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