Benzo b fluoranthene

The PAH4 standards benzo[a]pyrene (BaP, CAS No. 50-32-8), benzo[b]fluoranthene (BbF, CAS No. 205-99-2), chrysene (CHR, CAS No. 218-01-9), and benzo[a]anthracene (BaA, CAS No. 56-55-3) and internal standards (IS) 3-methylcholanthrene (CAS No. 56-49-5), chrysene-d12 (CAS No. 1719-03-5), and benzo[a]pyrene-d12 (CAS No. 63466-71-7) were obtained from Supelco, Inc. (Bellefonte, PA, USA). All materials and chemicals were of GC and HPLC analytical grade. Acetonitrile (ACN) (CAS No. 75-05-8), dichloromethane (DCM) (CAS No. 75-09-2), methanol (CAS No. 67-56-1), and hexane (CAS No. 110-54-3) were obtained from Burdick & Jackson (Muskegon, MI, USA). Sodium sulfate anhydrous (Na₂SO₄) (CAS No. 7757-82-6) 99% w/w purity; (Samchun Co., Ltd., Seoul, Korea) was used for dehydration. Distilled water (CAS No. 7732-18-5) and N,N-dimethylformamide (CAS No. 68-12-2) were prepared using a Milli-Q water purification system (Millipore, Billerica, MA, USA). Kovax syringes (3 mL) were obtained from Korea Vaccine Co., Ltd. (Gyeonggi-do, Korea). Polytetrafluoroethylene (PTFE) membrane filters (0.45 mm) were purchased from Advantec Co., Ltd. (Chiyoda City, Japan). Sep-Pak Florisil cartridges (Waters Corp., Milford, MA, USA) were utilized for solid-phase extraction (SPE).

Ground beef from beef chuck (7 g fat/100 g meat) was purchased from a local market in Bangkok, Thailand. Six flavonoids, including kaempferol, myricetin, quercetin, morin, rutin, and taxifolin were purchased from Sigma (St. Louise, MO, USA). We obtained 2,2-diphenyl-1picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS), potassium persulfate, 37% hydrochloric and sodium acetate acid from Aldrich (Steinheim, Germany). TPTZ (2,4,6-tri (2-picridyl)-triazine, Iron (III) chloride hexahydrate, Iron (II) Sulfate Heptahydrate of Grade AR were purchased from QRec (Auckland, New Zealand).
EPA PAH8: (benz(a)anthracene (BaA), chrysene (Chry), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), indeno(1,2,3-cd)pyrene (InP), dibenz(a,h)anthracene (DahA) and benzo(g,h,i)perylene (BghiP)) and QuEChERS kits were purchased from Supelco (Bellefonte, PA, USA). Internal standards (Acenaphthene-d10 and Chrysene-d12) were purchased from Dr. Ehrenstorfer (Augsburg, Germany), magnesium sulfate and sodium acetate were purchased from Ajax Finechem (Silverwater, NSW, Australia), all solvent high-performance liquid chromatography (HPLC) grade—(acetonitrile, methanol), ethanol (AR grade) and n-hexane (AR grade) were obtained from RCI Labscan (Bangkok, Thailand).

Standards PAH mix, including 16 mentioned PAHs (benzo(a)pyrene [BaP], acenaphthylene [Ace], naphthalene [NA], fluorene [F], acenaphthene [Ac], phenanthrene [Pa], fluoranthene [Fl], anthracene [A], benzo(a)anthracene [BaA], pyrene [P], benzo(b)fluoranthene [BbF], chrysene [Ch], benzo(k)fluoranthene [BkF], dibenzo[a,h]anthracene [DhA], indeno[1,2,3‐cd]pyrene [IP] and benzo[g,h,i]perylene [BgP]) was purchased from Supelco (Bellefonte, PA, U. S.). The standard solutions were prepared in dichloromethane, with all mentioned PAHs concentration of 0.1 mg/ml. Stock standard solutions were mixed with methanol‐dichloromethane (50:50, v/v) every week for the preparation of a working mixed solution (1 µg/ml for each mentioned PAHs) which was used to measure the extraction performance under various conditions. The working and stock solutions were preserved at 4°C and biphenyl was used as an internal standard at a concentration of 0.05 µg/ml in methanol. Multi‐walled carbon nanotubes were purchased from Hanwha Nanotech (MWCNT CM‐95, Korea) and the adsorbent of MWCNT‐MNP was prepared as described previously (Rastkari & Ahmadkhaniha, 2013). All other chemicals and solvents were of analytical grade.

The 8 PAHs listed in the WFD were selected (Table 2). Neat crystals of naphthalene and benzo(ghi)perylene were obtained from Fluka (St Louis, USA), anthracene and indeno(1,2,3-cd) were obtained from Dr Ehrenstorfer (Augsburg, DE) and fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene and benzo(a)pyrene were purchased from Sigma (St Louis, USA). The water samples simulating the dissolved phase were spiked with a standard solution prepared in acetonitrile containing the native compounds in a concentration range of 25.44 to 763.3 ng g⁻¹. The solution was stored in the dark at 4 °C until use.Table 2

Theoretical final concentrations of individual PAHs, PBDEs and TBT in the water test materials without SPM and the solvent used to spike them in the water

Compound(s)	Concentration (ng L−1)	Solvent
PAHs
Naphthalene	1200	Acetonitrile
Anthracene	100
fluoranthene	100
Benzo(b)fluoranthene	40
Benzo(k)fluoranthene	40
benzo(a)pyrene	50
Indeno(1,2,3-cd)pyrene	40
Benzo(ghi)perylene	40
PBDEs
∑BDE28, BDE47, BDE99,		Methanol
BDE100, BDE153, BDE154	4
TBT	5	Watera

^aThe stock solution and intermediate solution were prepared using acetic acid:methanol 3:1 (v/v); only the last dilution was made using Type-1 water

A composite standard solution of 18 PAHs including acenaphthene(ANA), acenaphthylene (ANY), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(g,h,i)perylene (BPE), chrysene (CHR), fluoranthene (FLT), fluorene (FLU), naphthalene (NAP), phenanthrene (PHE), anthracene (ANT), benzo(a)- anthracene (BEA), benzo(j)fluoranthene (BjF), benzo(a)pyrene (BaP), benzo(e)pyrene (BeP), bibenzo(a,h)anthracene (BaA), indeno(1,2,3-cd)pyrene (IPY) and pyrene (PYR) was purchased from Sigma-Aldrich (USA), each at a concentration of 1000 μg·mL⁻¹. N-hexane and acetonitrile were obtained from Chongqing Xinyu Chemical Reagent Co., Ltd. (China), both with an analytical grade.