Niskin bottles

Key et al. [27] have described improved methods for the measurement of radon and radium in seawater and marine sediments using manganese dioxide impregnated fibres. The basic method that these workers used was that of Broecker [28]. Seawater samples were taken in 30 litre Niskin bottles. 

It became possible to significantly increase the accuracy of measurements of dissolved oxygen in the 1990s, because oceanographers started to use the 5-L PVC Niskin bottles instead of 1-L bottles (the larger volume of water allowed better protection of the portion of water sampled in the flask from the oxygen inside the bottle). 

Simultaneous collections were made of water and suspended sediments by an Inter-Ocean pump sampling system, Niskin bottles with internal rubber closures, Niskin bottles with Teflon-coated coil springs, and newly designed Niskin bottles without internal closures. The samples were examined for contamination, particularly of trace metals. AU the sampling systems led to some metal contamination of the samples except the new Niskin bottles. However, each system was found acceptable for nutrient analysis. Because of its novel closure, the newly designed Niskin bottle is convenient for suspended material analysis. Samples may be filtered directly from the sampling bottle without contacting the atmosphere. 

Table II. Comparisons of Samples Collected by Three Designs of Niskin Bottle...

Figure 4, Top drop Niskin bottle with snap-on pressure fittings for filtration...

Bermuda Deep Sea Profile. Monaghan et al, (9) discuss a vertical profile of the water column (surface to bottom, 4500 m) obtained west of the Berumuda Islands using the chartered R/V Panularis. Sampling for extractable organics and nonvolatile hydrocarbons consisted of 13 casts of three 30-1. Niskin bottles. The casts were arranged so that the... 

Syiplinq, Discrete water column samples were obtained with 5-L Niskin bottles attached to a General Oceanics Rosette fitted with Plessey Environmental Systems model 9040 CTD. A 1-L aliquot of seawater was transferred from the Niskin samplers into glass-stoppered bottles in such a way that air bubbles were not trapped. The bottles were then stored in the dark at... 

Salinity-Temperature-Pressure (Depth). Conductivity, temperature and pressure data were collected using a Plessey Systems CTD with model 8400 data logger. These sensors were interrogated five times per second for values of temperature, conductivity (salinity), and pressure (depth). Data were recorded during the down-cast using a lowering rate of 30 m min". Niskin bottle samples were taken on every other cast to provide temperature and salinity calibration. Nominal precision of the salinity, temperature and depth measurments was 0.02 g kg", 0.02 °C and 0.2 m, respectively. 

A few liters of surface water can be sampled directly with cleaned glass bottles that can also be used for sample storage. For sampling at different depths, Go-flo or Niskin bottles are more suitable, and allow sampling volumes of up to 501. If it is not possible to extract the samples immediately after sampling, these are stored at temperatures below 0°C in stainless steel or glass containers, rinsed beforehand with pesticide grade acetone followed by n-hexane. 

Sampling with Niskin bottles, filtration through Millipore 0.45-4im, extraction with chloroform and ethyl acetate TLC, IR, GLC, MS Mediterranean Sea coastal waters dissolved hydrocarbons mean concentration 47 Mg r identification of Ci, C20 and C26 n-paraffins Copin and Barbier (1971)... 

Collection of samples at various depths with Niskin bottles, extraction of unfiltered small volumes (1 1) with carbon tetrachloride, collection of particulate hydrocarbons using a neuston sampler determination of hydrocarbons by fluorescence spectrophotometry. 

Sampling with Niskin bottles, filtration through fibreglass filter Whatman No. 1 extraction at pH 2 of large samples (201) with chloroform LC on silica gel, GLC... 

A Niskin bottle container, being lowered in the sea, is a measuring device used by oceanographers to collect water samples from different depths of the ocean. (PhotoStock-Israel/Photo Researchers, Inc.)... 

Water for the analysis of suspended particles may be collected with any clean water sampler used for oceanographic work, e.g., Niskin bottles, Go-Flo bottles, Nansen bottles. Hydrobios water samplers (see also Chapter 1). The sample volume will depend on the expected concentration of POM. In nearshore and/or biologically productive water, 0.5-2 L usually is an adequate sample volume. Ten litres may be required in particle-poor open ocean waters such as the Sargasso Sea. For sampling large volumes of water, 30 L Niskin bottles are recommended. Even larger volumes may be sampled with in situ pumps. (See Chapters 1,2 and 13). 

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