The authors thank Drs. Bobby J. Presley, Robert Tayloy, Paul Boothe, Mr. Bryan Brattin, and Mr. Mike Metcalf for their assistance during the laborious field sampling and lab work for the practical development and application of "clean techniques".

1. Numune Hazırlama <ol><li> örnekleyici <ol><li> sampler&#39;ın montajı <ol><li> 1.5 m, kimyasal olarak dayanıklı, silikon, pompalama borusunun (OD 0.635 cm) bir 4 m uzunluğunda fluorinatlı etilen propilen (FEP) boru (İD 0.635 cm OD 0.95 cm veya benzeri) takın. </li><li> pompalama tüpüne polipropilen Y-konnektörü yerleştirin ve diğer bir çıkışa ve (20 cm pompalama tüp ile) 0.45 mikron kapsül filtresine 50 cm pompalama tüp bağlayın. </li><li> bir temiz oda (tezgah) &#39;de borulama onlar temizlenir sonra (aşağıya bakınız) birleştirin ve polietilen torba iki kat topluluğu saklayın. </li></ol></li><li> Numune temizleme <ol><li> laboratuvar deterjan çözeltisi ile boru seti (bir peristaltik pompa üzerine 1,5 m pompalama tüpü takarak) doldurun ve 24 saat için bekletin. Daha sonra,% 10 (h / h) HCI ile (reaktif derecesi) ile doldurun ve 48 saat boyunca bekletin, de-iyonize su ile ayarlanmış boru yıkayın. </li><li> İyice W deiyonize ayarlanmış boru temizlemebirkaç kez bırakmayın, ve plastik torbalar içinde topluluğu saklayın. 24 saat boyunca bir% 50 (hac / hac) HNO 3 ile (reaktif derecesi) çözeltisi ıslatarak Y-bağlayıcıları ve kısa pompalama temiz tüplere. </li></ol></li><li> kapsül filtreleri <ol><li> Önce de-iyonize su ile 48 saatlik ıslatma adımı için, daha sonra,% 10 (h / h) HCI çözeltisi bunları yıkayarak kapsül filtreler temizleyin. </li><li> Asit Batırılıp ıslatılmadan sonra, de-iyonize su ile filtre yıkayın ve asidi nötralize etmek için, her filtrenin içine% 21 (ağırlık) NH4OH (alt haşlanmış) çözeltisi 1 ml. </li><li> polietilen fermuarlı çanta giriş ve çıkış, ve mağaza bağlayan 30 cm temizlenmiş pompalama tüpün bir döngü ile bireysel filtre mühür. </li></ol></li></ol></li><li> numune kapları <ol><li> Polietilen (PE, 1000 mi) ve FEP (500 mi, 1.000 mi) iz metal tespiti için konteynerler için şişe kullanın. <ol><li> % 50 daha sonra, deterjan (% 1) ilk (h / h) HNO 3 ıslatarak şişe temizleme(Reaktif derecesi) ve 24, 48 ve 24 saat süre ile,% 10 (h / h) HCI ile (reaktif derecesi) çözeltiler, sırasıyla iki ıslatma kademe arasındaki de-iyonize su ile şişe yıkayın. </li><li> son HCI iliklerine sonra, iyice de-iyonize su (DIW) ile şişe durulayın ve bir temiz oda veya sınıf-100 temiz tezgah (mühürlü kapaklı) şişe kurulayın. </li><li> polietilen fermuarlı çanta ve taşıma için polietilen torbalarda çift torba onları mühür temizlenmiş şişe. </li></ol></li><li> çözünmüş organik karbon (DOC) tayini için temiz bir cam şişeler <ol><li> 48 saat süre ile,% 10 HCl, çözünmüş organik karbon (DOC) analizi için, kehribar borosilikat cam şişe (40 mi) bekletin. de-iyonize su ile temizlenmiş cam şişe durulayın ve kullanımdan önce 2 saat boyunca 480 ° C &#39;de bunları yanma. taşıma için fermuarlı polietilen torbalarda ayrı ayrı şişeleri Seal. </li></ol></li></ol></li></ol> 2. Örnekleme <ol><li> Su numunesi toplama <ol><li> Upon örnekleme yerinde varış, dış torba üzerinde işareti örnek kimlik numarası ve orijinal torbalarda şişeleri tutun. </li><li> Nehir kıyısında ya da bir teknede anda, bir kişi örnekleyici ile çantayı açıp (temizlenmiş) 3 m polipropilen direğine 4-m FEP tüp takmak gerekir. mümkün olduğunca bankadan kutup uzatın ve yaklaşık 30 cm, pompa açılmadan önce nehir akan su yüzeyinin altında FEP boru girişi tutun. </li><li> başka bir kişinin bir peristaltik pompa (dahili pil ile örnekleme pompası) pompa kafasına pompalama tüp takmak zorunda. Pompayı başlatın ve su (aşağı tarafı) toplam numune hacmi en az 3 kez boşaltın. pudrasız eldiven giyin ve örnek şişeleri doldurarak başlatmak için şişe ve kapaklar çanta açın. <ol><li> Başka bir kişinin mevcut Alternatif olarak, eğer üçüncü şahıs iç çanta ve örnek kapaklar açılarak ve b içine örnek boşaltır örnekleme tüpünü tutan sorumlu olmak varottle. </li></ol></li><li> alanına iletkenlik, sıcaklık ve pH ölçümleri için 125 ml&#39;lik bir plastik şişe içinde bir süzülmemiş numune toplayın. </li><li> (1 (bir filtre olmadan çıkış ağzından) İlk (500 ml veya parçacık numune toplanması için 1000 ml) filtresiz örnekleri toplamak ve daha sonra bir filtrelenmiş su numunesi toplamak için kapsül filtre üzerinden gitmek için su zorlamak için plastik bir kelepçe ile çıkışı kapatın L) çözünmüş iz metal tayini için. </li><li> süzüldü örnekleri toplamak DOC ve EDTA ölçümleri için 40 ml amber cam şişeler içinde (filtre ile çıkıştan). </li><li> 1000 ml / dk, yaklaşık 500 ml / dk bir akış oranında su numuneleri toplamak. basıncı (filtreleri &#39;özelliklerine göre) kurmak için başladığında kapsül filtrelerini değiştirin. örneğin her türü için, kalite kontrol alikotları olarak hizmet etmek üzere seçilen konumlarda ilave örnekleri, aynı zamanda alan boşluklar, toplar. </li><li> kuru buz ve depolanan i 40 ml cam şişe yerleştirinbir buz göğüs ve buz sandıklarda polietilen şişeler n. </li></ol></li><li> asılı partikül madde Koleksiyon (SPM) <ol><li> plastik bir süzme hunisi ve kap kullanılarak, vakumla süzülerek 0.4 um polikarbonat (PC), membran filtreler üzerinde SPM (asit yıkandı ve önceden tartılmış) toplayın. </li><li> SPM konsantrasyonlar elde ve partikül iz metal tayini için parçacık örnekleri sağlamak için laboratuvarda kuru membran filtreleri dondurun. </li></ol></li></ol> 3. Numune Tedavi öncesi (İz Metaller Çözünmüş) <ol><li> Çözündürüldü eser metal belirlenmesi için, numune şişelerine 2 ml konsantre edilmiş alt kaynatılmış HNO 3 (1-L numune başına) ilave edilir. FEP şişe içine aktarın çözündürüldü eser metal örnekleri (asidifiye). Alternatif olarak, numuneler FEP şişeler doğrudan toplanabilir. 24 saat (8 ila 15 watt UV lambaları) için FEP şişelerde örnekleri UV-ışın tedavisi. </li></ol> Eser Metal Analizi 4. Önderiştirme ve Tedaviler <ol><li&gt; Önderiştirme reçine <ol><li> Küçük (10-30 mi kapasite) plastik bir kap içine katyon değiştirme reçinesi 2 g tartılır ve bir kap içine 2N HNO 3 solüsyonu az miktarda ilave edin. 10 ml kapasiteli kromatografi kolonu içine reçine dökün. 5 ml 2 N HNO 3 ile yıkanması reçineyi temizleme iki kez (-alt kaynatılmış) ve yüksek saflıkta su (HPW) ile 3 kez yıkayın. </li><li> NH 4 + -formu için reçine dönüştürmek için sütuna (alt haşlanmış) 1 M NH 4 OH 10 ml ekleyin. </li></ol></li><li> Tampon çözeltisi (1 M amonyum asetat) <ol><li> HPW yaklaşık 800 ml (alt kaynatılmış) buzlu asetik asit 57 ml ilave edilir. Amonyum hidroksit ~ 60 ml ilave edilir (% 21, haşlanmış-alt) ve asetik asit ile karıştırılır. 5.5 Nihai pH ve 1000 ml son ses seviyesini ayarlayın. </li></ol></li><li> Zenginleştirme işlemi (tortu metaller çözündürüldü) <ol><li> 30 ml 1 M amonyum Acet eklenerek 5.5 ± 0.3 olana kadar asitleştirildi, UV radyasyona tabi numunelerin pH ayarlamatampon çözelti ve bazı (~ 2.8 mi) NH 4 OH yedik örneklerin içine (alt haşlanmış). </li><li> ~ 30 katyonik değişim reçinesi (Bölüm 4.1) ile dolu sütunun üstünde cm ve ~ 60 cm FEP tüp ve kromatografi kap ve konnektör (dişi Luer) numune şişesi ve önderiştirme sütun bağlamak numune şişesi yerleştirin. </li><li> sütun üzerinde bağlı bir 2-yollu valf kullanılarak 3-5 ml / dak akış hızı, kontrol eder. Numuneler zenginleştirme sütunlar geçmesine izin verin. Numuneler sütunu geçtikten sonra, sütun tüpleri ve kapaklarını çıkarın. </li><li> 2 x 5 mi HPW 1 M amonyum asetat (pH 5.5) 4 x 5 ml ve diğer eser metaller Katyon ayırmak için HPW 2 x 5-ml sütunu tedavi edin. </li><li> Sadece sütunun altında 30 ml asitle yıkanmış PE şişe yerleştirin ve 7 x 1 ml 2 N HNO 3 ile sütun yıkayın PE şişe içine (alt haşlanmış). </li><li> Ağırlık a alarak 2 N HNO 3 atık (~ 8.0 ml) hacmi belirlemeknd 2 N HNO 3 atık özgül ağırlığı. </li></ol></li><li> asılı partikül madde sindirimi <ol><li> SPM örnekleri ile kuru PC filtreleri Freeze ve kuruduktan sonra onları tartın. Talep SPM örnekleri, önceden tartılmış perfloroalkoksi alkan Filtrelerin ile (PFA) damarlar (60 mi kapasite) ve damar içine konsantre HNO 3 3 ml ekleyin. </li><li> 2.5 kg-metre arasında bir sabit tork gemilere Sıkma ve 12 saat boyunca 130 ° C &#39;de, geleneksel bir fırın içinde dijeste edilmiştir. Soğuduktan sonra, gemileri açıp damarlarına HF 2 ml ekleyin. </li><li> 2.5 kg-metre arasında bir sabit tork gemilere Sıkma ve 12 saat boyunca 130 ° C &#39;de, geleneksel bir fırın içinde dijeste edilmiştir. Soğutulduktan sonra, damarlar açıp damarlarına% 4.5 borik asit çözeltisinin 16 mi ekleyin. </li><li> 2.5 kg-metre arasında bir sabit tork gemilere Sıkma ve 12 saat boyunca 130 ° C &#39;de, geleneksel bir fırında sindirimi. Her bir kap tartılır ve her özeti çözeltisinin özgül ağırlığını belirlerNihai sindirmek hacim elde edilir. </li><li> (Nihai filtre üzerinde numune ağırlığı bölü hacim özet), her bir filtre üzerinde SPM nihai hacim ve ağırlığından sindirimi için seyreltme faktörünü hesaplar. </li></ol></li></ol> 5. Numune Analizi <ol><li> iz metaller <ol><li> Önceden konsantre edilmiş numune ve alev atomik absorpsiyon spektrofotometresi, grafit fırın atomik absorpsiyon spektrofotometresi kullanılarak parçacıklardan çözeltisi çözündürüldü, ve / veya indüktif olarak bağlanmış plazma içindeki iz metalleri (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) konsantrasyonlarını belirlemek kütle spektrometresi. </li><li> indüktif eşleşmiş plazma-atomik emisyon spektrometresi ile zenginleştirme önce çizilmiş alt örnekleri ve asılı partiküler madde digests, büyük iyonlar konsantrasyonları ve bazı iz metaller, belirleyin. </li></ol></li><li> yardımcı parametreler <ol><li> taşınabilir cihazlar kullanarak, alanında örnek sıcaklık, pH, tuzluluk ve iletkenlik belirleyin. </li><li> Belirleme çözülmüş ya daKızılötesi spektrometresi 21 karbondioksit tespiti ile ıslak oksidasyon dayalı Ganiç karbon (DOC) Bir Toplam Organik Karbon Analiz tarafından konsantrasyonları. Yerleşik prosedürlere 22,23, aşağıdaki (a SPD-M10AV Diodearray dedektörü ile), yüksek performanslı sıvı kromatografisiyle toplam EDTA konsantrasyonunun belirlenmesi. </li></ol></li></ol>

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The authors have no conflict of interests to disclose.

doğal sularda güvenilir eser metal veri elde kirlenmeyi azaltmak amacı numune toplama, işleme, pretreatments ve analiz sırasında vurguladığı gibi büyük dikkat gerektirir. konsantrasyonları önceden bildirilen daha düşük büyüklükte emir olabilir bulundu son yirmi yılda &quot;temiz teknikleri&quot; kullanılarak elde edilen doğal sularda metal konsantrasyonları izleyin. eser metal düzeyleri doğru insanlar ve daha yüksek organizmalara zararlı etkilerinin daha iyi değerlendirilmesi sonucunda ölç?...

Yaygın doğal sular için elde edilen bazı eser metal sonuçları numune toplama, tedavi ve kararlılık 1,2 sırasında uygulanan yetersiz tekniklerden kaynaklanan eserler nedeniyle hatalı olabileceği kabul edilmiştir. Çözünmüş eser metallerin (yüzey sularında 3 nM aralığında alt nM) gerçek konsantrasyonları daha önce yayınlanan değerlerden daha düşük büyüklükte şimdi iki kararlarıdır. Aynı durum okyanus sularında kabul çözünmüş eser metal konsantrasyonları son 40 yılda büyüklüğe göre azalmıştır ya da öylesine gelişmiş örnekleme ve analitik yöntemler getirilmiştir gibi deniz kimyada bulunmuştur. Çabaları eser metal analizleri 4-8 tüm aşamalarında azaltılması veya iz metal kirlenmesi kaldırılmasına yönelik &quot;temiz teknikleri&quot; nin gelişmelere veri kalitesini artırmak için yapılmıştır. ortam sıcaklığında eser metal konsantrasyonlarının belirlenmesi içinseviyeleri, zenginleştirme sıklıkla gerekmektedir. İyon değiş tokuş teknikleri 8-12 yaygın verimli zenginleştirilmesi için uygulanmıştır. Kirlenme kapların duvarları ortaya çıkabilir, konteyner, sampler, numune işleme ve depolama, ve örnek korunması ve analiz 7,13 temizliği. Daha yakın zamanda gerçekleştirilen temiz yöntemlerle tüm çalışmalar, doğal sularda eser metal konsantrasyonları tipik olarak iyi rutin yöntemlerle 7 algılama sınırlarının altında olduğunu göstermektedir. 1990&#39;ların başında şüpheli eser metal verilerinin tanınması yana, temiz yöntemler iz metal tayini 14 ABD EPA (Çevre Koruma Ajansı) Rehberin içine dahil edilmiştir ve US Geological Survey 15 projeleri onların su kalitesinin izlenmesi için temiz yöntemler benimsemiştir. eser metal çalışmaları için temiz yöntemler sağlam ve doğru veri tabanı oluşturmak amacıyla tüm projelerde istihdam edilmek üzere gerekir. <pPrensip olarak class = &quot;jove_content&quot;&gt;, iz metal tayini için kullanılan su numuneleri belirli bir malzeme ve kompozisyon, enstrümantal analiz başlamadan önce, düzgün, uygun kaplar ve aparat kullanarak saklanan ve tedavi uygun örnekleme dişli alınmalıdır. asılı partikül madde (SPM) numune depolama süresi boyunca değişiklikler yapılabilir ve su bileşimi, su örneklerinden SPM hızlı ayırma değiştirebilir yana su ortamlarında eser metal çalışmaları için yaygın bir uygulamadır. doğal sularda çözündürüldü eser metal konsantrasyonlarının belirlenmesi için, süzme gereklidir ve satır filtreleme teknikleri, uygun ve etkili. Dağıtım ve yüzey ve yeraltı suları gibi sucul ortamlarda eser metallerin davranışı doğal (örneğin, hava) ve antropojenik etkilenebilir (örn atıksu atıklar) bu tür yeniden gibi faktörler, yanı sıra diğer çevre koşulları,Bölgesel jeoloji, morfoloji, arazi kullanımı ve bitki örtüsü, iklim 16-19. Bundan sonra, bu asılı partikül madde konsantrasyonları (SPM), çözünmüş organik karbon (DOC), insan kaynaklı ligand (örneğin, etilendiamintetraasetik asit, EDTA), bir tuzu, redoks potansiyeli ve pH 17-20 olarak fiziksel parametreleri farklılıklara neden olabilir. Bu nedenle, doğru ve alakalı eser metal çalışmaları uygun eser metal analizi için numune toplama yanı sıra ilgili faktörler ve parametrelerin belirlenmesini gerektirmektedir.

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			<td height="22" style="height:22px;width:249px;">Nitric Acid</td>
			<td style="width:216px;">Seastar Chemicals</td>
			<td style="width:129px;"></td>
			<td style="width:188px;">Baseline grade</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:249px;">Ammonium hydroxide</td>
			<td style="width:216px;">Seastar Chemicals</td>
			<td style="width:129px;"></td>
			<td>Baseline grade</td>
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		<tr height="22">
			<td height="22" style="height:22px;width:249px;">Acetic Acid</td>
			<td style="width:216px;">Seastar Chemicals</td>
			<td style="width:129px;"></td>
			<td>Baseline grade</td>
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		<tr height="22">
			<td height="22" style="height:22px;width:249px;">Nitric Acid</td>
			<td style="width:216px;">J. T. Baker</td>
			<td style="width:129px;">9601-05</td>
			<td>Reagent grade</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:249px;">Hydrochloric acid</td>
			<td style="width:216px;">J. T. Baker</td>
			<td style="width:129px;">9530-33</td>
			<td>Reagent grade</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">Chromatographic columns</td>
			<td style="width:216px;">Bio-Rad</td>
			<td>7311550&#160;</td>
			<td>Poly-Prep</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:249px;">Column stack caps</td>
			<td style="width:216px;">Bio-Rad</td>
			<td>7311555</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">Cap connectors (female luers)</td>
			<td style="width:216px;">Bio-Rad</td>
			<td style="width:129px;">7318223</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">2-way stopcocks</td>
			<td style="width:216px;">Bio-Rad</td>
			<td>7328102</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">Cation exchange resin</td>
			<td style="width:216px;">Bio-Rad</td>
			<td>1422832&#160;</td>
			<td>Chelex-100</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:249px;">Portable sampler (sampling pump)</td>
			<td style="width:216px;">Cole Palmer</td>
			<td>EW-07571-00</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">FEP tube</td>
			<td style="width:216px;">Cole Palmer</td>
			<td>EW-06450-07</td>
			<td>6.4 mm I.D., 9.5 mm O.D.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">Pumping tube</td>
			<td style="width:216px;">Cole Palmer</td>
			<td>EW-06424-24</td>
			<td>6.4 mm I.D. C-Flex</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">Capsule filter (0.4 mm)</td>
			<td style="width:216px;">Fisher Scientific</td>
			<td>WP4HY410F0</td>
			<td>polypropylene casing</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">1 L low density polyethylene bottle</td>
			<td>NALGE NUNC INTERNATIONAL</td>
			<td>312088-0032</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:249px;">1 L (or 500 ml) FEP bottle</td>
			<td>NALGE NUNC INTERNATIONAL</td>
			<td>381600-0032</td>
			<td></td>
		</tr>
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</table>

clean sampling and analysis of river and estuarine waters for trace metal studies

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination control. Developments of some techniques aiming to reduce trace metal contamination in the last couple of decades have resulted in concentrations reported now being orders of magnitude lower than those in the past. These low concentrations often necessitate preconcentration of water samples prior to instrumental analysis of samples. Since contamination can appear in all phases of trace metal analyses, including sample collection (and during preparation of sampling containers), storage and handling, pretreatments, and instrumental analysis, specific care needs to be taken in order to reduce contamination levels at all steps. The effort to develop and utilize "clean techniques" in trace metal studies allows scientists to investigate trace metal distributions and chemical and biological behavior in greater details. This advancement also provides the required accuracy and precision of trace metal data allowing for environmental conditions to be related to trace metal concentrations in aquatic environments.
This protocol that is presented here details needed materials for sample preparation, sample collection, sample pretreatment including preconcentration, and instrumental analysis. By reducing contamination throughout all phases mentioned above for trace metal analysis, much lower detection limits and thus accuracy can be achieved. The effectiveness of "clean techniques" is further demonstrated using low field blanks and good recoveries for standard reference material. The data quality that can be obtained thus enables the assessment of trace metal distributions and their relationships to environmental parameters.

gelişme &quot;temiz teknikler&quot; kullanımı ile, şimdi, ortam sularında doğru eser metal konsantrasyonları elde etmek için, suların örneklerde eser metallerin zenginleştirme yaygın bir uygulama olduğu kabul edilmektedir. doğal sularda eser metallerin en su kalitesi kriterleri düşük mikrogram / L aralığında iken, alt saptama limitleri sucul ortamlarda ortam konsantrasyonlarda iz metaller üzerinde jeokimyasal ve biyolojik etkilerini araştırmak için ihtiyaç vardı...

Watch this Scientific Journal Video about Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies at JoVE.com

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Special care using "clean techniques" is required to properly collect and process water samples for trace metal studies in aquatic environments. A protocol for sampling, processing, and analytical procedures with the aim of obtaining reliable environmental monitoring data and results with high sensitivity for detailed trace metal studies is presented.

Temiz Örnekleme ve Eser Metal Çalışmaları Nehri ve haliç Waters Analizi

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination ...

clean-sampling-analysis-river-estuarine-waters-for-trace-metal

Research

JoVE Journal

Environment

11.3K Görüntüleme.  National Sun Yat-sen University. Special care using "clean techniques" is required to properly collect and process water samples for trace metal studies in aquatic environments. A protocol for sampling, processing, and analytical procedures with the aim of obtaining reliable environmental monitoring data and results with high sensitivity for detailed trace metal studies is presented.

Video: Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Integrated Field Lysimetry and Porewater Sampling for Evaluation of Chemical Mobility in Soils and Established Vegetation

Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals is often not well understood. Here we demonstrate an integrated field lysimetry and porewater sampling method for evaluating the mobility of chemicals applied to soils and established vegetation. Lysimeters, open columns made of metal or plastic, are driven into bareground or vegetated soils. Porewater samplers, which are commercially available and use vacuum to collect percolating soil water, are installed at predetermined depths within the lysimeters. At prearranged times following chemical application to experimental plots, porewater is collected, and lysimeters, containing soil and vegetation, are exhumed. By analyzing chemical concentrations in the lysimeter soil, vegetation, and porewater, downward leaching rates, soil retention capacities, and plant uptake for the chemical of interest may be quantified. Because field lysimetry and porewater sampling are conducted under natural environmental conditions and with minimal soil disturbance, derived results project real-case scenarios and provide valuable information for chemical management. As chemicals are increasingly applied to land worldwide, the described techniques may be utilized to determine whether applied chemicals pose adverse effects to human health or the environment.

Field lysimetry and porewater sampling allow researchers to evaluate the fate of chemicals applied to soils and established vegetation. The goal of this protocol is to demonstrate how to install required instrumentation and collect samples for chemical analysis during integrated field lysimetry and porewater sampling experiments.

Entegre Saha Lysimetry ve gözenek suyu Örnekleme Topraklarda Kimyasal Hareketlilik Değerlendirilmesi ve kurulan Bitki Örtüsü

Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals ...

Çevre

Soil Sampling and Isolation of Entomopathogenic Nematodes (Steinernematidae, Heterorhabditidae)

Entomopathogenic nematodes (a.k.a. EPN) represent a group of soil-inhabiting nematodes that parasitize a wide range of insects. These nematodes belong to two families: Steinernematidae and Heterorhabditidae. Until now, more than 70 species have been described in the Steinernematidae and there are about 20 species in the Heterorhabditidae. The nematodes have a mutualistic partnership with Enterobacteriaceae bacteria and together they act as a potent insecticidal complex that kills a wide range of insect species.
Herein, we focus on the most common techniques considered for collecting EPN from soil. The second part of this presentation focuses on the insect-baiting technique, a widely used approach for the isolation of EPN from soil samples, and the modified White trap technique which is used for the recovery of these nematodes from infected insects. These methods and techniques are key steps for the successful establishment of EPN cultures in the laboratory and also form the basis for other bioassays that consider these nematodes as model organisms for research in other biological disciplines. The techniques shown in this presentation correspond to those performed and/or designed by members of S. P. Stock laboratory as well as those described by various authors.

Soil Sampling and Isolation of Entomopathogenic Nematodes Steinernematidae, Heterorhabditidae

Entomopathogenic nematodes are soil-inhabiting roundworms that parasitize a wide range of insects. We demonstrate sampling methods used for the isolation of these nematodes from the soil using two techniques: the insect baiting and the modified White trap, for the recovery of nematodes from soil samples and infected insect cadavers, respectively.

Toprak Örnekleme ve Entomopatojenik Nematodlar İzolasyonu (Steinernematidae, Heterorhabditidae)

Entomopathogenic nematodes (a.k.a. EPN) represent a group of soil-inhabiting nematodes that parasitize a wide range of insects. These nematodes belong to ...

A Whole Cell Bioreporter Approach to Assess Transport and Bioavailability of Organic Contaminants in Water Unsaturated Systems

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is not an appropriate measure for its availability; bioavailability rather depends on the dynamic interplay of potential mass transfer (flux) of a compound to a microbial cell and the capacity of the latter to degrade the compound. In water-unsaturated parts of the soil, mycelia have been shown to overcome bioavailability limitations by actively transporting and mobilizing organic compounds over the range of centimeters. Whereas the extent of mycelia-based transport can be quantified easily by chemical means, verification of the contaminant-bioavailability to bacterial cells requires a biological method. Addressing this constraint, we chose the PAH fluorene (FLU) as a model compound and developed a water unsaturated model microcosm linking a spatially separated FLU point source and the FLU degrading bioreporter bacterium Burkholderia sartisoli RP037-mChe by a mycelial network of Pythium ultimum. Since the bioreporter expresses eGFP in response of the PAH flux to the cell, bacterial FLU exposure and degradation could be monitored directly in the microcosms via confocal laser scanning microscopy (CLSM). CLSM and image analyses revealed a significant increase of the eGFP expression in the presence of P. ultimum compared to controls without mycelia or FLU thus indicating FLU bioavailability to bacteria after mycelia-mediated transport. CLSM results were supported by chemical analyses in identical microcosms. The developed microcosm proved suitable to investigate contaminant bioavailability and to concomitantly visualize the involved bacteria-mycelial interactions.

A whole cell bioreporter assay with Burkholderia sartisoli RP037-mChe was developed to detect fractions of an organic contaminant (i.e., fluorene) available for bacterial degradation after active transport by mycelia bridging air-filled pores in a water unsaturated model system.

A Whole Hücre Bioreporter Yaklaşımı Su Doymamış Sistemleri Organik Kontaminantların Taşıma ve Biyoyararlanımını Değerlendirmek için

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is ...

Sediment Core Sectioning and Extraction of Pore Waters under Anoxic Conditions

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is built and can be transported to a temporary work space close to field sampling site(s) to facilitate rapid analysis. Cores are extruded into a portable glove bag, where they are sectioned and each 1-3 cm thick section (depending on core diameter) is sealed into 50 ml centrifuge tubes. Pore waters are separated with centrifugation outside of the glove bag and then returned to the glove bag for separation from the sediment. These extracted pore water samples can be analyzed immediately. Immediate analyses of redox sensitive species, such as sulfide, iron speciation, and arsenic speciation indicate that oxidation of pore waters is minimal; some samples show approximately 100% of the reduced species, e.g. 100% Fe(II) with no detectable Fe(III). Both sediment and pore water samples can be preserved to maintain chemical species for further analysis upon return to the laboratory.

A protocol for sectioning sediment cores and extracting pore waters under anoxic conditions in order to permit analysis of redox sensitive species in both solids and fluids is presented.

Anoksik Koşullarında Tortu Çekirdek Kesit ve Gözenek Waters Ekstraksiyon

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is ...

Modification and Application of a Leaf Blower-vac for Field Sampling of Arthropods

Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as numbers per standardized sampling area. The sampling efficiency depends critically on the sampling duration. In a mature rice crop, a two-minute sampling in an enclosure of 0.13 m2 yields more than 90% of the arthropod population. The device also allows sampling of arthropods dwelling on the water surface or the soil in rice paddies, but it is not suitable for sampling fast flying insects, such as predatory Odonata or larger hymenopterous parasitoids. The modified blower-vac is simple to construct, and cheaper and easier to handle than traditional suction sampling devices, such as D-vac. The low cost makes the modified blower-vac also accessible to researchers in developing countries.

Assessment of arthropod abundance in crops is critical for investigating population dynamics and species interactions. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropods in rice.

Modifikasyon ve Arthropodların Saha Örnekleme için bir Yaprak Blower-vac Uygulama

Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the ...

Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of scientific publications address microplastic pollution of the sea surface. The protocol below describes the methodology for sampling, sample preparation, separation and chemical identification of microplastic particles. A manta net fixed on an &#187;A frame&#171; attached to the side of the vessel was used for sampling. Microplastic particles caught in the cod end of the net were separated from samples by visual identification and use of stereomicroscopes. Particles were analyzed for their size using an image analysis program and for their chemical structure using ATR-FTIR and micro FTIR spectroscopy. The described protocol is in line with recommendations for microplastics monitoring published by the Marine Strategy Framework Directive (MSFD) Technical Subgroup on Marine Litter. This written protocol with video guide will support the work of researchers that deal with microplastics monitoring all over the world.

The protocol below describes the methodology for: microplastics sampling on the sea surface, separation of microplastic and chemical identification of particles. This protocol is in line with the recommendations for microplastics monitoring published by the MSFD Technical Subgroup on Marine Litter.

Deniz Yüzey ve Numune Analizi Microplastics Örnekleme Protokolü

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of ...

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Microplastics act as vector of potentially toxic organic contaminants with unpredictable effects. This protocol describes an alternative methodology for assessing the levels of organochlorine pesticides adsorbed on plastic pellets and identifying the polymer chemical structure. The focus is on pressurized fluid extraction and attenuated total reflectance Fourier transform infrared spectroscopy.

Plastik Peletlerden Organochlorine Pestisitlerin Çıkarılması ve Plastik Tipi Analizi

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment ...

Determination of Inorganic Arsenic in a Wide Range of Food Matrices using Hydride Generation - Atomic Absorption Spectrometry.

The European Food Safety Authority (EFSA) underlined in its Scientific Opinion on Arsenic in Food that in order to support a sound exposure assessment to inorganic arsenic through diet, information about distribution of arsenic species in various food types must be generated. A method, previously validated in a collaborative trial, has been applied to determine inorganic arsenic in a wide variety of food matrices, covering grains, mushrooms and food of marine origin (31 samples in total). The method is based on detection by flow injection-hydride generation-atomic absorption spectrometry of the iAs selectively extracted into chloroform after digestion of the proteins with concentrated HCl. The method is characterized by a limit of quantification of 10 &#181;g/kg dry weight, which allowed quantification of inorganic arsenic in a large amount of food matrices. Information is provided about performance scores given to results obtained with this method and which were reported by different laboratories in several proficiency tests. The percentage of satisfactory results obtained with the discussed method is higher than that of the results obtained with other analytical approaches.

The usefulness of an analytical method to determine inorganic arsenic in a wide range of food matrices is demonstrated. The method consists of selective extraction of inorganic arsenic into chloroform with a final determination by hydride generation-atomic absorption spectrometry.

İnorganik arsenik içinde bir geniş aralığı, gıda hidrür üretimi - atomik Absorpsiyon spektrometresi kullanılarak matrisler belirlenmesi.

The European Food Safety Authority (EFSA) underlined in its Scientific Opinion on Arsenic in Food that in order to support a sound exposure assessment to ...

Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron (Oxy)Hydroxides, Trace Elements, and Bacteria

Fate and speciation of trace elements (TEs), such as arsenic (As) and mercury (Hg), in aquifers are closely related to physio-chemical conditions, such as redox potential (Eh) and pH, but also to microbial activities that can play a direct or indirect role on speciation and/or mobility. Indeed, some bacteria can directly oxidize As(III) to As(V) or reduce As(V) to As(III). Likewise, bacteria are strongly involved in Hg cycling, either through its methylation, forming the neurotoxin monomethyl mercury, or through its reduction to elemental Hg&#176;. The fates of both As and Hg are also strongly linked to soil or aquifer composition; indeed, As and Hg can bind to organic compounds or (oxy)hydroxides, which will influence their mobility. In turn, bacterial activities such as iron (oxy)hydroxide reduction or organic matter mineralization can indirectly influence As and Hg sequestration. The presence of sulfate/sulfide can also strongly impact these particular elements through the formation of complexes such as thio-arsenates with As or metacinnabar with Hg.
Consequently, many important questions have been raised on the fate and speciation of As and Hg in the environment and how to limit their toxicity. However, due to their reactivity towards aquifer components, it is difficult to clearly dissociate the biogeochemical processes that occur and their different impacts on the fate of these TE.
To do so, we developed an original, experimental, column setup that mimics an aquifer with As- or Hg-iron-oxide rich areas versus iron depleted areas, enabling a better understanding of TE biogeochemistry in anoxic conditions. The following protocol gives step by step instructions for the column set-up either for As or Hg, as well as an example with As under iron and sulfate reducing conditions.

Experimental Column Setup for Studying Anaerobic Biogeochemical Interactions Between Iron OxyHydroxides, Trace Elements, and Bacteria

Fate and speciation of arsenic and mercury in aquifers are closely related to physio-chemical conditions and microbial activity. Here, we present an original experimental column setup that mimics an aquifer and enables a better understanding of trace element biogeochemistry in anoxic conditions. Two examples are presented, combining geochemical and microbiological approaches.

Demir (oksi) hidroksit, eser elementler ve bakteri anaerobik biyojeokimyasal Hofstede çalışmak için deneysel sütun Kur

Fate and speciation of trace elements (TEs), such as arsenic (As) and mercury (Hg), in aquifers are closely related to physio-chemical conditions, such as ...

An Ultra-clean Multilayer Apparatus for Collecting Size Fractionated Marine Plankton and Suspended Particles

The distributions of many trace elements in the ocean are strongly associated with the growth, death, and re-mineralization of marine plankton and those of suspended/sinking particles. Here, we present an all plastic (Polypropylene and Polycarbonate), multi-layer filtration system for collection of suspended particulate matter (SPM) at sea. This ultra-clean sampling device has been designed and developed specifically for trace element studies. Meticulous selection of all non-metallic materials and utilization of an in-line flow-through procedure minimizes any possible metal contamination during sampling. This system has been successfully tested and tweaked for determining trace metals (e.g., Fe, Al, Mn, Cd, Cu, Ni) on particles of varying size in coastal and open ocean waters. Results from the South China Sea at the South East Asia Time-Series (SEATS) station indicate that diurnal variations and spatial distribution of plankton in the euphotic zone can be easily resolved and recognized. Chemical analysis of size-fractionated particles in surface waters of the Taiwan Strait suggests that the larger particles (&#62;153 &#181;m) were mostly biologically derived, while the smaller particles (10 - 63 &#181;m) were mostly composed of inorganic matter. Apart from Cd, the concentrations of metals (Fe, Al, Mn, Cu, Ni) decreased with increasing size.

Plankton and suspended particles play a major role in the biogeochemical cycles in the ocean. Here, we provide an ultra-clean, low stress method for the collection of various sizes of particles and plankton at sea with the capability of handling large volumes of seawater.

Şeker boyutu deniz Plankton ve askıya alınan parçacıkları toplamak için Ultra temiz bir çok katmanlı aparat

The distributions of many trace elements in the ocean are strongly associated with the growth, death, and re-mineralization of marine plankton and those ...